Operating Manual Agilent Technologies Single Input Electronic Load Family Agilent Part No. 5951-2826 Microfiche Part No.
CERTIFICATION Agilent Technologies. certifies that this product met its published specifications at time of shipment from the factory. Agilent Technologies further certifies that its calibration measurements are traceable to the United States National Bureau of Standards, to the extent allowed by the Bureau’s calibration facility, and to the calibration facilities of other International Standards Organization members.
SAFETY SUMMARY The following general safety precautions must be observed during all phases of operation, service, and repair of this instrument. Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design, manufacture, and intended use of the instrument. Agilent Technologies assumes no liability for the customer’s failure to comply with these requirements. BEFORE APPLYING POWER.
SAFETY SUMMARY (continued) GENERAL Any LEDs used in this product are Class 1 LEDs as per IEC 825-l. This ISM device complies with Canadian ICES-001. Cet appareil ISM est conforme à la norme NMB-001 du Canada. ENVIRONMENTAL CONDITIONS This instruments is intended for indoor use in an installation category II, pollution degree 2 environment. It is designed to operate at a maximum relative humidity of 95% and at altitudes of up to 2000 meters.
DECLARATION OF CONFORMITY according to ISO/IEC Guide 22 and EN 45014 Manufacturer’s Name: Agilent Technologies, Inc. Manufacturer’s Address: New Jersey Division 150 Green Pond Road Rockaway, NJ 07866 U.S.A.
Table of Contents 1. General Information What’s in this Manual ................................................................................................................................9 Reader Path ................................................................................................................................................9 Options ..................................................................................................................... ..................................
Table of Contents (continued) Controller Connection ................................................................................................................................39 GPIB Connector ......................................................................................................................................39 GPIB Address..........................................................................................................................................
Table of Contents (continued) Calibration Commands...............................................................................................................................76 Calibration Flowcharts ...............................................................................................................................77 Example Program .......................................................................................................................................77 A.
1 General Information What’s In This Manual This chapter contains specifications that apply to the Single Input Electronic Load Family as well as information concerning options and safety requirements.
Safety Requirements This product is a Safety Class 1 instrument, which means that it is provided with a protective earth ground terminal. This terminal must be connected to an ac source that has a 3-wire ground receptacle. Review the instrument rear panel and this manual for safety markings and instructions before operating the instrument. Refer to the Safety Summary page at the beginning of this manual for a summary of general safety information.
Table 1-1. Specifications (continued) DERATED CURRENT DETAIL CONSTANT CURRENT MODE Ranges Low Range: High Range: Accuracy (after 30 sec wait): Regulation: CONSTANT RESISTANCE MODE Ranges Low Range: Middle Range: High Range: Accuracy Low Range: Middle and High Ranges: CONSTANT VOLTAGE MODE Range: Accuracy: Regulation: TRANSIENT OPERATION Modes: Continuous Mode Freq Range: Freq Accuracy: Duty Cycle Range: 6060B 6063B 0 to 6 A 0 to 60 A ± 0.1% ± 75 mA both ranges 0 to 1 A 0 to 10 A ± 0.
Table 1-1. Specifications (continued) TRANSIENT CURRENT LEVEL Ranges Low Range: High Range: Accuracy Low Range: High Range: 0 to 6 A 0 to 60 A 0 to 1 A 0 to 10 A ± 0.1% ± 80 mA ± 0.1% ± 350 mA ± 0.18% ± 13 mA ± 0.18% ± 50 mA 6060B 6063B 0.033 to 1 Ω 1 to 1000 Ω 10 to 10,000 Ω 0.20 to 24 Ω 24 to 10,000 Ω 240 to 50,000 Ω ±0.8% ± 10 m Ω with ≥ 6 A at input ± 0.3% ± 10 mS with ≥ 6 V at input ± 0.3% ± 10 mS with ≥ 6 V at input ± 0.8% ± 200 m Ω with ≥ 1 A at input ± 0.3% ± 0.
Table 1-2. Supplemental Characteristics 6060B 6063B 1.6 mA 16 mA 100 ppm/°C ±5 mA/°C both ranges 0.26 mA 2.6 mA 150 ppm/°C ±1 mA/°C both ranges 0.27 mΩ 0.27 mS 0.027 mS 6 mΩ 0.011 mS 0.001 mS 800 ppm/°C ± 0.4 mΩ/°C 300 ppm/°C ± 0.6 m S/°C 800 ppm/°C ± 10 mΩ/°C 300 ppm/°C ± 0.
Table 1-2. Supplemental Characteristics (continued) VOLTAGE READBACK Resolution: Temperature Coefficient: Maximum Readback Capability: EXTERNAL ANALOG PROGRAMMING Bandwidth: Accuracy Low Current Range: High Current Range: Voltage Range: Temperature Coefficient Current Range: Voltage Range: 6060B 6063B 17 mV (via GPIB) 20 mV (front panel) 50 ppm/°C ± 1.
Table 1-2. Supplemental Characteristics (continued) Fuse: The ac input is protected by a fuse located in a module on the rear panel; 0.5AM for l00/120 Vac input; 0.25AM for 220/240 Vac input. Maximum VA: 60 Peak Inrush Current: 2.5 A (typical) PROGRAMMABLE SLEW RATE: (For any given input transition, the time required will be either the total slew time or a minimum transition time, whichever is larger. The minimum transition time increases when operating with input currents under 1 AM (6060B) or 0.
Table 1-2. Supplemental Characteristics (continued) Voltage Slew Rate: Rate # 6060B (0 to 60V) Voltage Step 1 2 3 4 5 6 7 8 9 6063B (0 to 240V) Voltage Step 1 V/ms 2.5 V/ms 5 V/ms 10 V/ms 25 V/ms 50 V/ms 0.1 V/µs 0.25 V/µs 0.5 V/µs Transition Time* 4 V/ms 10 V/ms 20 V/ms 40 V/ms 100 V/ms 200 V/ms 0.4 V/µs 1 V/µs 2 V/µs 8.0 ms 3.2 ms 1.6 ms 800 µs 320 µs 160 µs 100 µs 100 µs 100 µs *Transition time is based on low capacitance current source.
Table 1-2. Supplemental Characteristics (continued) SOURCE TURN-ON CURRENT OVERSHOOT (In CC and CR modes when connected to power supplies with voltage rise times of greater than 500 µs) 6060B <10% 6063B <5% 0.033 ohm (0.02 ohm typ) 0.20 ohm (0.10 ohm typ) 20 k (typical) 80 k (typical) ± 0.03% ± 10 mA ± 0.01% ± 10 mV ± 0.03% ± 15 mA ± 0.
2 Operation Overview Introduction The Electronic Load is used for design, manufacturing, and evaluation of dc power supplies, batteries, and power components. The primary operating features of the Electronic Load are: constant current (CC) mode, constant voltage (CV) mode, or constant resistance (CR) mode. The input can also be turned on or off (open circuit) or short circuited. Other features include a built-in GPIB interface and a built-in pulse generator.
Local/Remote Control Local (front panel) control is in effect immediately after power is applied. The front panel keypad and display allow manual control when the Electronic Load is used in bench test applications. Remote (computer) control goes into effect (front panel Rmt annunciator is on) as soon as the Electronic Load receives a command via the GPIB.
Figure 2-1. Constant Current Mode Immediate Current Level and ENTRY keys) or via the GPIB (CURR command). If the CC The current level can be set at the front panel ( mode is the active mode, the new setting immediately changes the input at a rate determined by the slew setting (described below). If the load is not in the CC mode, the new setting is saved for use when the mode is changed to CC.
Slew Rate Slew rate determines the rate at which the input level changes to a new programmed value. Slew rate can be set at the front panel ( , and ENTRY keys) or via the GPIB (CURR:SLEW command). This slew rate remains in effect for the immediate, triggered, and transient level changes previously described. There are 12 discrete current slew rates within each slew-rate range.
Triggered Resistance Level The resistance level can be preset (stored in the Electronic Load) allowing the input level to change when a trigger is received instead of immediately as previously described. The resistance level can only be preset via the GPIB (RES:TRIG command). The preset capability is not available at the front panel. If the CR mode is the active mode, the preset resistance level will become the actual value and the input will be updated when a trigger occurs.
Immediate Voltage Level and ENTRY keys) or via the GPIB (VOLT command). If the CV The voltage level can be set at the front panel ( mode is the active mode, the new setting immediately changes the input level at a rate determined by the voltage slew setting. If the load is not in the CV mode, the new setting is saved for use when the mode is changed to CV.
For example, assume that the CC mode is active, the slew rate is at the default setting (maximum rate), and the applicable transient operation parameters have been set as follows: HPSL Command Description TRAN:MODE CONT CURR 5 CURR:TLEV 10 TRAN:FREQ 1000 TRAN:DCYC 40 TRAN ON Sets continuous operation. Sets main current level to 5 amps. Sets transient current level to 10 amps. Sets transient generator frequency to 1 kHz. Sets transient generator duty cycle to 40%. Turns on transient operation.
HPSL Command Description TRIG:SOUR EXT TRAN:MODE PULS CURR 5 CURR:TLEV 10 TRAN:TWID .001 TRAN ON Selects the external trigger input. Selects pulsed transient operation. Sets main current level to 5 amps. Sets transient current level to 10 amps. Sets pulse width to 1 millisecond. Turns on transient operation. Figure 2-5 shows the waveform that would result in this pulsed transient operation example. The Electronic Load starts conduction at the main current level setting (5 amps).
Figure 2-6 shows the waveform that would result for this toggled transient operation example. Operation is similar to that described for continuous and pulse operation, except that each time a trigger is received the input alternates between the main and transient current levels. Figure 2-6. Toggled Transient Operation Triggered Operation The Electronic Load has various triggering modes to allow synchronization with other test equipment or events.
In cases where the transition from one setting to another is large, the actual transition time can be calculated by dividing the voltage or current transition by the slew rate. The actual transition time is defined as the time required for the input to change from 10% to 90% or from 90% to 10% of the programmed excursion. In cases where the transition from one setting to another is small, the small signal bandwidth of the load limits the minimum transition time for all programmable slew rates.
Short On/Off A load can simulate a short circuit at its input by turning the load on with full-scale current. The short circuit can be toggled on/off at the front panel ( key) or via the GPIB (INPUT:SHORT ON|OFF command). The short on/off change uses the slew rate setting of the active mode and range. Figure 2-8. Transition Times and Slew Rates The actual value of the electronic short is dependent on the mode and range that are active when the short is turned on.
Input On/Off key) or via the GPIB (INPUT ON|OFF command). A load’s input can be toggled on/off at the front panel ( The input on/off change does not use the slew rate setting so the input will change at the maximum slew rate. Turning the input off (zero current) does not affect the programmed settings. The input will return to the previously programmed values when the input is turned on again. Note that the Input On/Off command supersedes the mode commands and Short On/Off command.
Protection Features The Electronic Load includes the following protection features: • • • • • Overvoltage Overcurrent (hardware and software) Overpower (hardware and software) Overtemperature Reverse Voltage The appropriate bits in the status registers are set when any of the above protection features are active. Also, the Prot annunciator comes on and the front-panel alphanumeric display indicates which conditions have been detected.
If the software overcurrent limit is exceeded and persists beyond the specified delay time, the input is turned off. Also, for these conditions, the OC and PS (protection shutdown) status register bits are set and will remain set until the OC condition is removed and the bits are reset as previously described. Overpower Nominal Power Limit. The nominal power-limit boundary is set by software that monitors the input current and voltage.
Monitor Outputs The IMON and VMON output signals indicate the input current and voltage. A 0-to-10V signal at the appropriate output indicates the zero-to-full scale input current or voltage. An external DVM or oscilloscope can be connected to monitor the input voltage and current. External Programming Input CC and CV modes can be programmed with a signal (ac or dc) connected to the Ext Prog input. A 0-to-10V external signal corresponds to the 0-to-full scale input range in CV mode or in CC mode.
Port On/Off Port is a general purpose output port that can be used to control an external device such as a relay for power supply test purposes. The output is toggled on and off via the GPIB (PORT0 ON | OFF command). It cannot be controlled from the front panel. The Port output signal is a TTL compatible signal that becomes active (high level) when the PORT command is programmed ON and becomes inactive (low level) when the PORT command is programmed OFF.
3 Installation Introduction This chapter discusses how to install and make connections to the rear panel of your Electronic Load. A turn-on checkout procedure as well as application considerations for specific operating modes are also discussed. Inspection When you receive your Electronic Load, inspect it for any obvious damage that may have occurred during shipment. If there is damage, notify the carrier immediately and notify the nearest Agilent Sales Office.
Location and Cooling Table 1-1 gives the dimensions of the Electronic Load. The cabinet has plastic feet that are shaped to ensure self-alignment when stacked with other Agilent System II cabinets. The feet may be removed for rack mounting. Your Electronic Load must be installed in a location that allows sufficient space at the sides and rear of the unit for adequate air circulation. The unit can be mounted in a standard 19-inch rack panel or enclosure.
Line Voltage 100/120 Vac 220/240 Vac 7. Fuse 0.5 AT 0.25 AT Agilent Part No. 2110-0803 2110-0817 Re-install fuse holder and connect the line cord. Figure 3-3. Voltage Select Switches Figure 3-4.
Connect The Power Cord Your Agilent Electronic Load was shipped with a power cord for the type of outlet used at your location. Connect the power cord to the ac input socket. SHOCK HAZARD The power cord provides a chassis ground through a third conductor. Be certain that your power outlet is of the three-conductor type with the correct pin connected to earth ground (see Figure 3-1). Turn-On/Selftest Turn on the Electronic Load using the LINE switch on the front panel and observe the display.
Power Test Note The following checkout assumes that the Electronic Load is set to the factory defaults listed in Table 4-6. Refer to Chapter 4 if you need to recall the factory default values. Use a power supply with the voltage set to 10 V and the current limit set to 10 A to check the input circuits. The settings of the power supply were only selected to agree with the following procedure. You can use different settings, but you must set the Electronic Load accordingly. 1.
Do not stack more than three connector blocks together on any GPIB connector. The resultant leverage can exert excessive force on the mounting panels. Make sure that all connectors are fully seated and that the lock screws are firmly handtightened. Use a screwdriver only for the removal of the screws. GPIB Address The GPIB address of the Electronic Load is factory set to address 5. The GPIB address can only be set using the front panel and ENTRY keys. Chapter 4 explains how to change the GPIB address.
3. Hand tighten the adjustment knob to secure the wire in the binding post. If you are using a slotted screwdriver, tighten the knob to 8 in.-lbf for a secure connection. Installation for the optional front panel binding posts is the same as for the rear terminal binding posts. Do not use lubricants or contact cleaners on the binding posts. Certain chemical agents can damage the LEXAN material of the binding post, causing the part to fail. Figure 3-8.
+S and -S Used to connect the remote sense leads to the power source. Pin 1 connects the + S signal and pin 2 connects the - S signal. IM and VM (pins 3 and 4) Used to monitor the Electronic Load’s input current and voltage. A 0 V-to-10 V signal at the appropriate pin indicates the zero-to-full scale current or voltage. Pin 3 monitors current (IM); pin 4 monitors voltage (VM). Common (pin 5) Provides the common connection for the IM, VM, and external programming (Ext Prg) signals.
Trigger Connector A four-pin connector block (TB201) connector and a quick-disconnect mating plug (RTB2) are provided for input and output trigger signals (see Figure 3-10). Consistent with good engineering practice, all leads connected to the trigger connector should be twisted and shielded to maintain the instrument’s specified performance. Figure 3-10. Trigger Connector TRIG IN (pin 1) A TTL-compatible input that responds to low-level external trigger signals.
Application Connections Wiring Considerations FIRE HAZARD To satisfy safety requirements, load wires must be heavy enough not to overheat while carrying the short-circuit output current of the device connected to the Electronic Load. Refer to Table 3-1 for the ampere capacity of various stranded wire sizes. Input connections are made to the + and - binding posts on the panel. (Input connections can also be made to the optional front panel binding posts).
Parallel Connections Figure 3-13 illustrates how Electronic Loads can be paralleled for increased power dissipation. Up to six Electronic Loads can be directly paralleled in CC or CR mode. Units cannot be paralleled in CV mode. Each Electronic Load will dissipate the power it has been programmed for. For example, if two Electronic Loads are connected in parallel, with Electronic Load number 1 programmed for 10 A and module number 2 programmed for 20 A, the total current drawn from the source is 30 A.
Figure 3-11. Local Sensing Figure 3-12.
Figure 3-13. Parallel Operation Figure 3-14.
4 Local Operation Introduction The “Operation Overview” chapter introduced you to the Electronic Load's features and capabilities and briefly described how to control the unit locally from the front panel and remotely with a computer via the GPIB. This chapter describes in greater detail how to operate the Electronic Load from the front panel.
Item 3 Electronic Load Status Annunicators Table 4-1. Controls and Indicators (continued) Description CC-Indicates the Electronic Load is in the constant current (CC) mode. Note that Figure 4-1 shows the Electronic Load is in the CC mode (CC annunciator is on). CR-Indicates the Electronic Load is in the constant resistance (CR) mode. CV-Indicates the Electronic Load is in the constant voltage (CV) mode. Tran-Indicates that transient operation is enabled.
Item 6 FUNCTION Keys Table 4-1. Controls and Indicators (continued) Description - Returns the display to the metering function selected, the display will show the measured input voltage and current, the computed input power, or certain status conditions (e.g. INPUT SHORT ON, OC, etc.). Press the Meter key to continually step through the displays. - Displays the setting for current (C:RNG) or resistance (R:RNG), depending upon which function is selected. The settings can be changed using the ENTRY keys.
Item 6 FUNCTION Keys (continued) Table 4-1. Controls and Indicators (continued) Description - Displays the resistance setting. (e.g. RES 1000). This setting can be changed using the ENTRY keys. The RES key also selects the CR mode (MODE RES) in conjunction with the MODE and Enter keys. - Displays the voltage setting (e.g. VOLT 5.567). This setting can be changed using the ENTRY keys. The VOLT key also selects the CV mode (MODE VOLT) in conjunction with the MODE and Enter keys. 7 ENTRY Keys to and 7.
• • • • • "INPUT OFF" (if active) "SHORT ON" Volts/Amps input metering, for example, "9.99 0.99" Computed power value, for example "9.9 WATTS" Protection Features (if any are active): "VF"-voltage fault "OV"-overvoltage "RV"-reverse voltage "PS"-protection shutdown "OC"-overcurrent "OP"-overpower "OT"-overtemperature If the display is metering the input voltage/current or the computed power, you can use the Input ENTRY keys to increase or decrease the actual input.
Note The CC, CR, and CV values described in subsequent paragraphs can be programmed whether or not the associated mode is active. When a mode is selected, all of the associated values will take effect at the input provided that the input is turned on. Figure 4-2.
Setting the Mode of Operation The present (active) mode of operation is indicated by the appropriate annunciator being on (e.g. CC). The active mode can also be viewed on the display by pressing . For example, "MODE CURR" indicates that the CC mode is active. You can change the mode to CR or CV by pressing the which changes the display to "MODE applicable key. To change the mode of operation from CC to CR, first press . As soon as the Enter key is pressed, the CR annunciator goes on, the RES".
Changing the programming range can cause the present CC settings (main level, transient level, and slew rate) to be automatically adjusted to fit within the new range. For example, assume that you are programming the Agilent 6060B 300 Watt Electronic Load, the present range is 0 to 60A "C:RNG 60.000", and the present CC settings are: "CURR 10.000" - main level is 10 A "C:TLV 12.000" - transient level is 12 A "C:SLW 5.0000" - slew rate is 5 A/µs If you now select the 0 to 6 A range "C:RNG 6.
b. Press again and note that the display indicates "C:TLV 1.0000". Note that you can use the Input ENTRY keys to increment and decrement the transient current level. Operation is similar to that described above for the main current level. Setting CR Values The CR values are programmed by pressing the applicable FUNCTION keys and then setting the desired value using the ENTRY keys. The display identifies the selected function; for example, R:RNG identifies resistance range.
"RES 50.000" - main level is 50 ohms "R:TLV 40.000" - transient level is 40 ohms "C:SLW.50000" - slew rate is 0.5 A/µs (1 to 1 k ohms range uses the CC slew rate setting). If you now select the low range (R:RNG 1.0000), the settings will automatically be changed to fit into the new range as follows: "RES 1.0000" - main level is 1 ohm (maximum value low range) "R:TLV 1.0000" - transient level is 1 ohm (maximum value low range) "V:SLW 5.0000" - slew rate is 5 V/µs (low range uses the CV slew rate setting).
4. Set Transient Level-The transient resistance level "R:TLV" is meaningful only if transient operation (described later) is turned on. a. Set the transient level to 0.8 ohm by pressing . Remember that in the low range the transient level must be set higher than the main level. b. Press again and note that the display indicates "R:TLV 0.8000". Note that you can use the Input ENTRY keys to increment and decrement the transient resistance level.
Note that you can use the ENTRY keys to increment ( ) or decrement ( ) the main VOLT level setting. You can see the VOLT setting being incremented or decremented one step at a time each time you press the applicable Input key. The values are entered automatically. (You don’t press the Enter key.) Remember if the CV mode is active, the incremented or decremented values will immediately change the actual input. 2. Set Slew Rate a. First press (blue shift key) and note that the Shift annunciator goes on.
a. Set the main CC level to 0.5 amps, the transient CC level to 1 amp, and the slew rate to 0. 0025 A/µs. See examples under Setting CC Values. b. Turn on CC mode by pressing: 2. Set frequency to 5 kHz by pressing: 3. Set duty cycle to 25% by pressing: (blue shift key) (shifted) 4. Turn on transient operation by pressing: 5. Note that the Tran annunciator is on. Shorting The Input The Electronic Load can simulate a short circuit across its input. The short circuit can be toggled on/off by pressing .
Setting The Electronic Load’s GPIB Address Before you can program the Electronic Load remotely via a GPIB computer, you must know its GPIB address. You can . The Electronic Load’s GPIB address will be displayed; for example "ADDRESS 5". find this out by pressing The Electronic Load is shipped from the factory with its address set to 5. If you want to leave the address set at 5, you can return to the metering mode by pressing the Meter key. If you want to change the address, you can enter a new value.
Table 4-6. Factory Default Settings Function Setting 6060B 6063B Input on/off on on Short on/off off off CURR level 0A 0A CURR transient level 0A 0A CURR slew rate 1 A/µs 0.83 A/µs CURR range 60 A 10 A *CURR protection level 61.2 A 10.
Recalling the Factory Default Values You can recall the factory default values (see Table 4-6) for all modules by pressing: . As soon as the Enter key is pressed, the Electronic Load will be set to its factory default values. Note that the Electronic Load is also set to the factory default values when the *RST common command is sent via the GPIB (see the Programming Reference Guide).
5 Remote Operation Introduction Chapter 4 - Local Operation described how to program the Electronic Load manually using the front panel keys. This chapter describes the fundamentals of programming the Electronic Load remotely from a GPIB controller The similarities between local and remote programming will become apparent as you read this chapter. The intent of this chapter is to help first time users quickly become familiar with operating their Electronic Load remotely from a GPIB controller.
Sending A Remote Command To send the Electronic Load a remote command, combine your computer’s output statement with the GPIB interface select code, the GPIB device (Electronic Load) address, and finally the Electronic Load’s HPSL command. For example, to set the input current of a previously specified channel to 10 amps, send: Getting Data Back The Electronic Load is capable of reading back the values of parameter settings as well as its actual input voltage and current or computed input power.
1. Modes The CC, CR, and CV values can be programmed whether or not the associated mode is active. If the input is turned on, all of the applicable values will take effect at the input when the associated mode is selected. 2. Ranges Changing the CC or CR programming range can cause the present settings to be automatically adjusted to fit within the new range. See Setting CC Values and Setting CR Values in Chapter 4.
Figure 5-1.
Figure 5-1.
CC Mode Example This example sets the current level to 0.75 amps and then reads back the actual current value. 10 OUTPUT 705;"INPUT OFF" 20 OUTPUT 705;"MODE:CURR" 30 OUTPUT 705;"CURR:RANG 1" 40 OUTPUT 705;"CURR 0.75" 50 OUTPUT 705;"INPUT ON" 60 OUTPUT 705;"MEAS:CURR?" 70 ENTER 705;A 80 DISP A 90 END Line 10: Line 20: Line 30: Line 40: Line 50: Line 60: Line 70: Line 80: Turns off Electronic Load input. Selects the CC mode. Selects the low current range. Sets the current level to 0.75 amps.
70 OUTPUT 705;”INPUT ON" 80 OUTPUT 705;”MEAS:POW?" 90 ENTER 705;A 100 DISP A 110 END Line 10: Line 20: Line 30: Line 40: Line 50: Line 60: Line 70: Line 80: Line 90: Line 100: Turns off Electronic Load input. Selects the CR mode. Sets the current protection limit to 2 A with a trip delay of 5 seconds. Enables the current protection feature. Selects the middle range. Sets the resistance level to 100 ohms. Turns on Electronic Load input.
80 OUTPUT 705;"TRAN ON 90 OUTPUT 705;"INPUT ON" . . . . 200 OUTPUT 705;"*TRG" 210 END Line 10: Line 20: Line 30: Line 40: Line 50: Line 60: Turns off Electronic Load input. Selects the CR mode. Selects the main resistance level to 10 ohms. Sets the transient resistance level to 5 ohms. Remember in the 1 to 1k range, the transient resistance level must be set to a lower level than the main resistance level. Selects the GPIB as the trigger source. Sets the current slew rate to the fastest rate.
Function Constant Resistance (CR) Set Range Low Range Middle Range High Range Set Main Level Low Range Middle Range High Range Set Slew Rate Low Range Middle/High Range Set Transient Level *Set Triggered Level Constant Voltage (CV) Set Main Level Set Slew Rate Set Transient Level *Set Triggered Level Transient Operation Set Frequency Set Duty Cycle *Set Pulse Width Current Protection *Set Current Level *Set Delay Time Table 5-1.
6 Calibration Introduction This chapter describes the calibration procedures for the Electronic Load and gives a sample calibration program. The Electronic Load should be calibrated annually, or whenever certain repairs are made (refer to the Service Manual). Calibration is accomplished entirely in software by sending calibration constants to the Electronic Load via the GPIB. This means that the Electronic Load can be calibrated without removing its cover, or removing it from its cabinet if rack mounted.
Figure 6-1. Calibration Equipment Setup Calibration Commands The following calibration commands are required to calibrate the Electronic Load. They are used in the program examples included in this section. Refer to the Agilent Electronic Loads Programming Reference Guide for HPSL commands. CALibration:[MODE] ON|OFF| Turns the calibration mode on or off. CALibration:LEVel:HIGH Enters the actual high level value (measured by an external instrument) that corresponds to the present high level setting.
CALibration:SAVE Writes the present calibration constants into the EEPROM. This command does not have to be sent until all ranges and modes have been calibrated. If the unit is turned off before CAL:SAVE is sent, the new calibration constants are lost Calibration Flowcharts The flowchart in Figures 6-2 describes the calibration procedure. It corresponds to the example calibration program. The flowchart indicates the appropriate statement that is used in the program example to accomplish each step.
Table 6-2.
Figure 6-2.
Figure 6-2.
Figure 6-2.
Program Listing 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 370 380 390 400 410 420 430 440 450 460 470 480 490 500 510 ASSIGN @Ld TO 705 Chan=l OUTPUT @Ld;”CHAN”;Chan;”;CAL ON" Cal_curr(@Ld,Chan,Hi_curr_rng,Hi_curr_offset,l) Cal_curr(@Ld,Chan,Lo_curr_rng,Lo_curr_offset,0) Cal_volt(@Ld,Chan,Volt_hipt,Volt_lopt) Cal_res(@Ld,Chan,Lo_res_rng,Lo_res_hipt,Lo_res_lopt,0) Cal_res(@Ld,Chan,Mid_res_rng,Mid_res_hipt,Mid_res_lo
Program Listing (continued) 520 530 540 550 560 570 580 590 600 610 620 630 640 650 660 670 680 690 700 710 720 730 740 750 760 770 780 790 800 810 820 830 840 850 860 870 880 890 900 910 920 930 940 950 960 970 980 990 1000 1010 1020 OUTPUT @Ld;"*TRG" IF Flag THEN WAIT 30 INPUT "Enter current through shunt for high point in amps",Trpt_curr OUTPUT @Ld;"CAL:TLEV";Trpt_curr OUTPUT @Ld;"TRAN OFF" PRINT "Test unit to verify that transient values are in spec" PRINT "Press CONT when ready to calibrate next range
Program Listing (continued) 1030 1040 1050 1060 1070 1080 1090 1100 1110 1120 1130 1140 1150 1160 1170 1180 1190 1200 1210 1220 1230 1240 1250 1260 1270 1280 1290 1300 1310 1320 1330 1340 1350 1360 1370 1380 1390 1400 1410 1420 1430 1440 1450 84 ! SUB Cal_res(@Ld,Chan,Res_rng,Res_hipt,Res_lopt,Flag) PRINT "RESISTANCE CALIBRATION, RANGE";Res_rng PRINT "Set power supply to calibration information table" PRINT "Press CONT when ready to continue" PAUSE OUTPUT @Ld;"CHAN";Chan OUTPUT @Ld;"MODE:RES" OUTPUT @Ld;
Explanation LINE 10-20 LINE 30 LINE 40-90 LINE 100 LINE 110 LINE 140 LINE 200-220 LINE 230 LINE 240 LINE 260 LINE 270 LINE 280 LINE 300 LINE 310 LINE 350 LINE 360-370 LINE 380-390 LINE 400 LINE 410 LINE 430 LINE 440 LINE 500 LINE 550-560 LINE 570 LINE 590 LINE 600 LINE 610 LINE 630 LINE 640 LINE 680 LINE 690-700 LINE 710-720 LINE 730 LINE 750 LINE 760 LINE 820 LINE 870-890 LINE 900 LINE 930-940 LINE 950 LINE 980-990 LINE 1030-1070 LINE 1080-1090 LINE 1100 LINE 1110-1150 LINE 1160 LINE 1190-1200 LINE 1210 S
A Considerations For Operating In Constant Resistance Mode The Agilent Electronic Loads implement Constant Resistance. (CR) mode by using either the CV circuits or CC circuits to regulate the input. The low range is regulated with the CV circuits, using the input current monitor as the reference. Therefore, resistance is described by the formula V I =R in which input current I is the reference, and voltage at the input terminals, V, is the parameter controlled to determine the resistance of the load.
If large resistances are required, the accuracy can be improved by reading the voltage and current directly from the load, calculating the actual resistance, and then adjusting the programmed value accordingly. This technique is most practical in applications requiring a fixed resistive load. The following examples illustrate the worst-case error possibilities resulting from op amp offsets. The examples are based on a 300-watt unit having 1 ohm, 1 kilohm, and 10 kilohm ranges.
INDEX A aliases ..........................................................................................................................................................................21 ampere-capacity...........................................................................................................................................................46 annunciators..........................................................................................................................................
INDEX (continued) G GPIB address ...................................................................................................................................................42, 64, 67 GPIB connector ...........................................................................................................................................................41 GPIB device ........................................................................................................................................
INDEX (continued) O output statement...........................................................................................................................................................67 overcurrent.............................................................................................................................................................33, 55 overload condition ............................................................................................................................
INDEX (continued) software current limit...................................................................................................................................................33 status reporting ......................................................................................................................................................32, 55 system keys.................................................................................................................... ....................
Agilent Sales and Support Offices For more information about Agilent Technologies test and measurement products, applications, services, and for a current sales office listing, visit our web site: http://www.agilent.com/find/tmdir You can also contact one of the following centers and ask for a test and measurement sales representative. United States: Agilent Technologies Test and Measurement Call Center P.O.
Manual Updates The following updates have been made to this manual since the print revision indicated on the title page. 4/15/00 All references to HP have been changed to Agilent. All references to HP-IB have been changed to GPIB.
