DriveIT Low Voltage AC Drives Embedded Fieldbus (EFB) Control Modbus®, Metasys® N2 and APOGEE® FLN Protocols for ACH550-01/02/U1/U2 Drives
ACH550 Drive Manuals GENERAL MANUALS ACH550-01/UH User's Manual (0.
Table of Contents Table of Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Embedded Fieldbus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Embedded Fieldbus Overview The ACH550 can be set up to accept control from an external system using standard serial communication protocols. When using serial communication, the ACH550 can either: • Receive all of its control information from the fieldbus, or • Be controlled from some combination of fieldbus control and other available control locations, such as digital or analog inputs, and the control panel.
Control Interface In general, the basic control interface between the fieldbus system and the drive consists of: Protocol Control Interface Reference for more information Modbus • Output Words – Control word – Reference1 – Reference2 • Input Words – Status word – Actual value 1 – Actual value 2 – Actual value 3 – Actual value 4 – Actual value 5 – Actual value 6 – Actual value 7 – Actual value 8 The content of these words is defined by profiles.
Mechanical and Electrical Installation – EFB Warning! Connections should be made only while the drive is disconnected from the power source. Drive terminals 28…32 are for RS485 communications. • Use Belden 9842 or equivalent. Belden 9842 is a dual twisted, shielded pair cable with a wave impedance of 120 Ω. • Use one of these twisted shielded pairs for the RS485 link. Use this pair to connect all A (-) terminals together and all B (+) terminals together.
Communication Set-up – EFB Serial Communication Selection To activate the serial communication, set parameter 9802 COMM PROTOCOL SEL = • 1 (STD MODBUS). • 2 (N2) • 3 (FLN) • 5 (BACNET) Note! If you cannot see the desired selection on the panel, your drive does not have that protocol software in the application memory. Serial Communication Configuration Setting 9802 automatically sets the appropriate default values in parameters that define the communication process.
EFB Protocol Reference Code Description 5304 EFB PARITY Defines the data length, parity and stop bits to be used with the RS485 link communication. • The same settings must be used in all on-line stations. 0 = 8N1 – 8 data bits, No parity, one stop bit. 1 = 8N2 – 8 data bits, No parity, two stop bits. 2 = 8E1 – 8 data bits, Even parity, one stop bit. 3 = 8O1 – 8 data bits, Odd parity, one stop bit.
Activate Drive Control Functions – EFB Controlling the Drive Fieldbus control of various drive functions requires configuration to: • Tell the drive to accept fieldbus control of the function. • Define as a fieldbus input, any drive data required for control. • Define as a fieldbus output, any control data required by the drive. The following sections describe, at a general level, the configuration required for each control function.
Input Reference Select Using the fieldbus to provide input references to the drive requires: • Drive parameter values set as defined below. • Fieldbus controller supplied reference word(s) in the appropriate location. (The location is defined by the Protocol Reference, which is protocol dependent.) Protocol Reference Drive Parameter Value Setting Modbus DCU PROFILE ABB DRV 1102 EXT1/EXT2 SEL 8 (COMM) Reference set selection by fieldbus. 1103 REF1 SEL 8 (COMM) Input reference 1 by fieldbus.
Miscellaneous Drive Control Using the fieldbus for miscellaneous drive control requires: • Drive parameter values set as defined below. • Fieldbus controller supplied reference word(s) in the appropriate location. (The location is defined by the Protocol Reference, which is protocol dependent.) Protocol Reference Drive Parameter Value Setting Modbus ABB DRV 1601 RUN 40001 bit 3 40031 bit 6 (inverted) BO4 35 8 (COMM) Fault reset by fieldbus.
Relay Output Control Using the fieldbus for relay output control requires: • Drive parameter values set as defined below. • Fieldbus controller supplied reference word(s) in the appropriate location. (The location is defined by the Protocol Reference, which is protocol dependent.) Protocol Reference Drive Parameter Value Modbus Setting ABB DRV N2 DCU PROFILE FLN 1401 RELAY OUTPUT 1 35 (COMM) Relay Output 1 controlled by fieldbus.
Analog Output Control Using the fieldbus for analog output control requires: • Drive parameter values set as defined below. • Fieldbus controller supplied reference word(s) in the appropriate location. (The location is defined by the Protocol Reference, which is protocol dependent.
Feedback from the Drive – EFB Pre-defined Feedback Inputs to the controller (drive outputs) have pre-defined meanings established by the protocol. This feedback does not require drive configuration. The following table lists a sample of feedback data. For a complete listing, see input word/point/object listings in the technical data for the appropriate protocol starting on page 19.
Actual Value Scaling The scaling of actual values can be protocol dependent. In general, for Actual Values, scale the feedback integer using the parameter’s resolution. (See "Parameter Descriptions" section in ACH550 User’s Manual for parameter resolutions.) For example: Feedback Integer Parameter Resolution (Feedback Integer) * (Parameter Resolution) = Scaled Value 1 0.1 mA 1 * 0.1 mA = 0.1 mA 10 0.1% 10 * 0.
Diagnostics – EFB Fault Queue for Drive Diagnostics For general ACH550 diagnostics information, see "Diagnostics" section in ACH550 User’s Manual. The three most recent ACH550 faults are reported to the fieldbus as defined below. Drive Parameter Protocol Reference Modbus N2 FLN 0401 Last Fault 40401 17 90 0412 Previous Fault 1 40402 18 91 0413 Previous Fault 2 40403 19 92 Serial Communication Diagnostics Network problems can be caused by multiple sources.
Loss of Communication The ACH550 behavior, if communication is lost, was configured in "Communication Fault". The parameters are 3018 COMM FAULT FUNC and 3019 COMM FAULT TIME. The "Parameter Descriptions" section in ACH550 User’s Manual describes these parameters in detail. No Master Station on Line If no master station is on line: Neither the EFB OK MESSAGES nor the errors (5307 EFB CRC ERRORS and 5308 EFB UART ERRORS) increase on any of the stations.
Intermittent Off-line Occurrences The problems described above are the most common problems encountered with ACH550 serial communication. Intermittent problems might also be caused by: • Marginally loose connections, • Wear on wires caused by equipment vibrations, • Insufficient grounding and shielding on both the devices and on the communication cables.
Modbus Protocol Technical Data Overview The Modbus® protocol was introduced by Modicon, Inc. for use in control environments featuring Modicon programmable controllers. Due to its ease of use and implementation, this common PLC language was quickly adopted as a de-facto standard for integration of a wide variety of master controllers and slave devices. Modbus is a serial, asynchronous protocol. Transactions are half-duplex, featuring a single Master controlling one or more Slaves.
Mapping Summary The following table summarizes the mapping between the ACH550 (parameters and I/0) and Modbus reference space. For details, see "Modbus Addressing" below.
The following table summarizes the 0xxxx reference set: Modbus Ref.
The ACH550 supports the following Modbus function codes for coils: Function Code Description 01 Read coil status 05 Force single coil 15 (0x0F Hex) Force multiple coils 1xxxx Mapping – Modbus Discrete Inputs. The drive maps the following information to the 1xxxx Modbus set called Modbus Discrete Inputs: • Bit-wise map of the STATUS WORD (selected using parameter 5305 EFB CTRL PROFILE). The first 32 inputs are reserved for this purpose.
Modbus Ref.
The following table summarizes the 4xxxx drive control registers 40001…40099 (for 4xxxx registers above 40099, see the drive parameter list, e.g. 40102 is parameter 0102): Modbus Register Access Remarks 40001 CONTROL WORD R/W Maps directly to the profile‘S CONTROL WORD. Supported only if 5305 = 0 or 2 (ABB Drives profile). Parameter 5319 holds a copy in hex format. 40002 Reference 1 R/W Range = 0…+20000 (scaled to 0…1105 REF1 MAX), or -20000…0 (scaled to 1105 REF1 MAX…0).
For the Modbus protocol, drive parameters in group 53 report the parameter mapping to 4xxxx Registers. Code Description 5310 EFB PAR 10 Specifies the parameter mapped to Modbus register 40005. 5311 EFB PAR 11 Specifies the parameter mapped to Modbus register 40006. 5312 EFB PAR 12 Specifies the parameter mapped to Modbus register 40007. 5313 EFB PAR 13 Specifies the parameter mapped to Modbus register 40008. 5314 EFB PAR 14 Specifies the parameter mapped to Modbus register 40009.
Actual Values The contents of the register addresses 40005…40012 are ACTUAL VALUES and are: • Specified using parameters 5310…5317. • Read-only values containing information on the operation of the drive. • 16-bit words containing a sign bit and a 15-bit integer. • When negative values, written as the two’s complement of the corresponding positive value. • Scaled as described earlier in "Actual Value Scaling". Exception Codes Exception codes are serial communication responses from the drive.
ABB Control Profiles Technical Data Overview ABB Drives Profile The ABB Drives profile provides a standard profile that can be used on multiple protocols, including Modbus and the protocols available on the FBA module. Two implementations of the ABB Drives profile are available: • ABB DRV FULL – This implementation standardizes the control interface with ACS600 and ACS800 drives. • ABB DRV LIM – This implementation standardizes the control interface with ACS400 drives.
ABB Drives Profile The following table and the state diagram later in this sub-section describe the CONTROL WORD content for the ABB Drives Profile.
ABB Drives Profile (EFB) CONTROL WORD Bit 7 Name RESET RESET Fault reset if an active fault exists (Enter SWITCH-ON INHIBITED). Effective if 1604 = COMM. 0 OPERATING Continue normal operation Unused 10 Unused (ABB DRV LIM) 12…15 Comments 0=>1 8…9 11 Commanded State Value REMOTE_CMD (ABB DRV FULL) 1 Fieldbus control enabled. 0 • CW =/ 0 or Ref =/ 0: Retain last CW and Ref. • CW = 0 and Ref = 0: Fieldbus control enabled. • Ref and deceleration/acceleration ramp are locked.
DCU Profile CONTROL WORD (See Parameter 0301) Bit 8 9 10 11 12 13 14 15 Name Value STPMODE_EM STPMODE_C RAMP_2 RAMP_OUT_0 RAMP_HOLD RAMP_IN_0 RREQ_LOCALLOC TORQLIM2 Command/Req.
ABB Drives Profile The following table and the state diagram later in this sub-section describe the status word content for the ABB Drives Profile.
DCU Profile The following tables describe the STATUS WORD content for the DCU profile. DCU Profile STATUS WORD (See Parameter 0303) Bit 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Name READY ENABLED STARTED RUNNING ZERO_SPEED ACCELERATE DECELERATE AT_SETPOINT LIMIT SUPERVISION REV_REF REV_ACT PANEL_LOCAL FIELDBUS_LOCAL EXT2_ACT FAULT ABB Control Profiles Technical Data Value Status 1 Drive is ready to receive start command. 0 Drive is not ready. 1 External run enable signal received.
DCU Profile STATUS WORD (See Parameter 0304) Bit 16 17 18 19 20 Name ALARM REQ_MAINT DIRLOCK LOCALLOCK CTL_MODE Value Status 1 An alarm is on. 0 No alarms are on. 1 A maintenance request is pending. 0 No maintenance request is pending. 1 Direction lock is ON. (Direction change is locked out.) 0 Direction lock is OFF. 1 Local mode lock is ON. (Local mode is locked out.) 0 Local mode lock is OFF. 1 Drive is in vector control mode. 0 Drive is in scalar control mode.
State Diagram ABB Drives Profile To illustrate the operation of the state diagram, the following example (ABB DRV LIM implementation of the ABB Drives profile) uses the control word to start the drive: • First, the requirements for using the CONTROL WORD must be met. See above. • When the power is first connected, the state of the drive is not ready to switch on. See dotted lined path ( ) in the state diagram below.
The state diagram below describes the start-stop function of CONTROL and STATUS WORD (SW) bits for the ABB Drives profile.
Reference Scaling ABB Drives and DCU Profiles The following table describes REFERENCE scaling for the ABB Drives profile. ABB Drives and DCU Profiles Reference Range Reference Type Scaling Remarks REF1 -32767 … +32767 Speed or frequency -20000 = -(par. 1105) 0=0 +20000 = (par. 1105) (20000 corresponds to 100%) Final reference limited by 1104/1105. Actual motor speed limited by 2001/2002 (speed) or 2007/2008 (frequency). REF2 -32767 … +32767 Speed or frequency -10000 = -(par.
ABB Drives and DCU Profiles Reference REF1 Value Setting COMM*AI1 AI Reference Scaling COMM (%) * (AI (%) / 0.5*REF1 MAX (%)) Fieldbus Reference Correction Coefficient 200% 100% AI1 Input Signal (100 - 0.5 * (par. 1105))% REF2 COMM+AI1 COMM 0% 50% 100% (%) + (AI (%) - 0.5*REF2 MAX (%)) Fieldbus Reference Correction Coefficient (100 + 0.5 * (Par. 1108)% 100% AI1 Input Signal (100 - 0.5 * (par. 1108)% REF2 COMM*AI1 COMM 0% 50% 100% (%) * (AI (%) / 0.
Reference Handling Use group 10 parameters to configure for control of rotation direction for each control location (EXT1 and EXT2). The following diagrams illustrate how group 10 parameters and the sign of the fieldbus reference interact to produce REFERENCE values (REF1 and REF2). Note, fieldbus references are bipolar, that is they can be positive or negative. ABB Drives Profile Parameter 1003 DIRECTION Value Setting AI Reference Scaling 1 (FORWARD) Resultant Ref. Max.
N2 Protocol Technical Data Overview The N2 Fieldbus connection to the ACH550 drives is based on an industry standard RS-485 physical interface. The N2 Fieldbus protocol is a master-slave type, serial communication protocol, used by the Johnson Controls Metasys® system. In the Metasys architecture the N2 Fieldbus connects object interfaces and remote controllers to Network Control Units (NCUs). The N2 Fieldbus can also be used to connect ACH550 drives to the Metasys Companion product line.
• Change of State (COS) enabled • Alarm Enabled • Warning Enabled • Override value is received, but there is no action taken. Binary Input – The binary input objects support the following features: • Binary Input actual value • Normal / Alarm state specification • Alarm Enabled • Change of State (COS) enabled • Override value is received, but there is no action taken.
The following diagram shows the drives’ integration to the Johnson Controls Metasys Companion system. PC-Version PC Version Panel Version/LTD Panel Version/LTD Converter Converter RS232 -RS485 N2 Fieldbus On the N2 Fieldbus each ACH550 drive can be accessed by the full complement of Metasys FMS features, including Change-of-State (COS) monitoring, alarm notification, scheduling, trend, and totalization.
N2 Analog Inputs: Number Object Drive Parameter Scale Factor Units Range AI9 MEGAWATT HOURS 0141 1 MWh 0…999 AI10 RUN TIME 0114 1 H 0…9999 AI11 DC BUS VOLTAGE 0107 1 V 0…999 AI12 OUTPUT VOLTAGE 0109 1 V 0…999 AI13 PRC PID FEEDBACK 0130 10 % 0…100 AI14 PRC PID DEVIATION 0132 10 % 0…100 AI15 EXT PID FEEDBACK 0131 10 % 0…100 AI16 EXT PID DEVIATION 0133 10 % 0…100 AI17 LAST FAULT 0401 1 fault code AI18 PREV FAULT 0402 1 fault code AI19 OLDEST
N2 Binary Inputs: Number Object Drive Parameter Range BI15 INPUT 6 STATUS 0119 (bit mask 01) 0 = Off, 1 = On BI16 EXTERNAL 2 SELECT Status Word 0 = EXT1 = EXT2 BI17 HAND/AUTO Status Word 0 = AUTO, 1 = HAND BI18 ALARM Status Word 0 = OK, 1 = ALARM BI19 MAINTENANCE REQ Status Word 0 = OK, 1 = MAINT REQ BI20 DRIVE READY Status Word 0 = Not Ready, 1 = Ready BI21 AT SETPOINT Status Word 0 = No, 1 = At Setpoint BI22 RUN ENABLED Status Word 0 = Not Enabled, 1 = Enabled BI23
N2 Binary Output Objects The following table lists the N2 Binary Output objects defined for the ACH550 drive.
CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI CSAI "AI1",N,N,"FREQ_ACT","Hz" "AI2",N,N,"PCT_ACT","%" "AI3",N,N,"SPEED","RPM" "AI4",N,N,"CURRENT","A" "AI5",N,N,"TORQUE","%" "AI6",N,N,"POWER","kW" "AI7",N,N,"DRV_TEMP","°C" "AI8",N,N,"ENERGY_k","kWh" "AI9",N,N,"ENERGY_M","MWh" "AI10",N,N,"RUN_TIME","H" "AI11",N,N,"DC_VOLT","V" "AI12",N,N,"VOLT_ACT","V" "AI13",N,N,"PID1_ACT","%" "AI14",N,N,"PID2_DEV","%" "AI15",N,N,"PID2_ACT","%" "AI1
CSBI CSBI CSAO CSAO CSAO CSAO CSAO CSAO CSAO CSAO CSAO CSAO CSAO CSAO CSAO CSAO CSAO CSAO CSAO CSAO CSAO CSAO CSBO CSBO CSBO CSBO CSBO CSBO CSBO CSBO CSBO CSBO CSBO CSBO CSBO CSBO CSBO CSBO CSBO CSBO CSBO CSBO "BI25",N,N,"N2_R1SRC","NO","YES" "BI26",N,N,"N2_R2SRC","NO","YES" "AO1",Y,Y,"REF_1","%" "AO2",Y,Y,"REF_2","%" "AO3",Y,Y,"ACCEL_1","s" "AO4",Y,Y,"DECEL_1","s" "AO5",Y,Y,"CURR_LIM","A" "AO6",Y,Y,"PID1_GN","%" "AO7",Y,Y,"PID1_I","s" "AO8",Y,Y,"PID1_D","s" "AO9",Y,Y,"PID1_FLT","s" "AO10",Y,Y,PID2_GN",
FLN Protocol Technical Data Overview The FLN fieldbus connection to the ACH550 drives is based on an industry standard RS-485 physical interface. The FLN (Floor Level Network) Fieldbus protocol is a serial communication protocol, used by the Siemens APOGEE® system. The ACH550 interface is specified in Siemens application 2734. Supported Features The ACH550 supports all required FLN features. Reports The ACH550 provides seven pre-defined reports.
FLN Startup Report Point # Type 94 LDO Subpoint Name Data RESET FAULT Overview FLN Overview Report Point # Type Subpoint Name 03 LAI FREQ OUTPUT 04 LAI PCT OUTPUT 05 LAI SPEED 06 LAI CURRENT 07 LAI TORQUE 08 LAI POWER 09 LAI DRIVE TEMP 10 LAI DRIVE KWH 11 LAI DRIVE MWH 12 LAI RUN TIME 13 LAI DC BUS VOLT 14 LAI OUTPUT VOLT 17 LAI MOTOR TEMP 18 LAI MREV COUNTER 21 LDI FWD.REV 23 LDI STOP.RUN 25 LDI EXT1.
FLN Drive I/O Report Point Subpoint Name # Type 45 LDO RO 6 COMMAND 46 LAO AO 1 COMMAND 47 LAO AO 2 COMMAND 70 LDI DI 1 ACTUAL 71 LDI DI 2 ACTUAL 72 LDI DI 3 ACTUAL 73 LDI DI 4 ACTUAL 74 LDI DI 5 ACTUAL 75 LDI DI 6 ACTUAL 76 LDI RO 1 ACTUAL 77 LDI RO 2 ACTUAL 78 LDI RO 3 ACTUAL 79 LDI RO 4 ACTUAL 80 LDI RO 5 ACTUAL 81 LDI RO 6 ACTUAL 85 LAI AO 2 ACTUAL Data Drive Config FLN Drive Config.
Process PID FLN Process PID Report Point # Type Subpoint Name 15 LAI PRC PID FBCK 16 LAI PRC PID DEV 50 LAO PRC PID GAIN 51 LAO PRC PID ITIM 52 LAO PRC PID DTIM 53 LAO PRC PID DFIL 54 LDO PRC PID SEL 60 LAO INPUT REF1 61 LAO INPUT REF2 82 LAI AI 1 ACTUAL 83 LAI AI 2 ACTUAL 84 LAI AO 1 ACTUAL 85 LAI AO 2 ACTUAL Data Each host FLN application (e.g. CIS or Insight) controls both the particular data reported for each point, and the report format.
• Calculate the new slope as follows: (Desired Range, i.e. high - low values) x (Slope of Existing Point) New Slope = = Range of Existing Point (60 Hz - 0 Hz) x (0.01) 100% - 0% = 0.006 Example – You are controlling water temperature from a cooling tower using the ACH550 to control a fan. The temperature sensor has a range of 30 to 250 degrees Fahrenheit.
Point Database The following table lists the point database for FLN / ACH550 (Application 2734). FLN Point Database Point # Subpoint Name Factory Default Engr. Units Type Slope Intercept On Text Off Text (SI Units) 01 LAO CTLR ADDRESS 99 - 1 02 LAO APPLICATION 2734 - 1 {03} LAI FREQ OUTPUT 0 Hz 0.1 {04} LAI PCT OUTPUT 0 PCT {05} LAI SPEED 0 {06} LAI CURRENT {07} LAI {08} - - - - 0 - - 0.1 0 - - RPM 1 0 - - 0 A 0.1 - - TORQUE 0 PCT 0.
FLN Point Database Point # Subpoint Name Factory Default Engr. Units Type Slope Intercept On Text Off Text (SI Units) {34} LDI ENA.DIS ACT DISABL - 1 0 ENABLE DISABL {35} LDO ENA.
FLN Point Database Point Factory Default Subpoint Name Engr. Units Slope Intercept On Text Off Text # Type (SI Units) 66 LDO SPD OUT MIN 0 PCT 0.1 0 - - 67 LDO SPD OUT MAX 1000 PCT 0.
Detailed Point Descriptions FLN Detailed Point Descriptions Point Drive Parameter Description 1 CTRL ADDRESS The FLN address of the drive. It can be set by FLN and by the panel. 5302 2 APPLICATION The Application ID for FLN on the ACH550. This ID is assigned by Siemens for each unique application. It correlates directly to a particular point list approved at the time of release. Therefore, this point list shall remain fixed once approval is granted.
FLN Detailed Point Descriptions Point Description Drive Parameter 21 FWD.REV ACT Indicates the rotational direction of the motor, regardless of control source (1 = REV, 0 = FWD). 22 FWD.REV CMD Commanded by FLN to change the rotational direction of the drive. • Parameter 1001 must be set to COMM for FLN to control the direction of the motor by EXT1. • Parameter 1002 must be set to COMM for FLN to control the direction of the motor by EXT2. 23 RUN.
FLN Detailed Point Descriptions Point Drive Parameter Description 37 FLN CTL SRC Indicates if FLN is a source for control inputs (1 = YES, 0 = NO). Note that this status point is true if any of the following control inputs are from FLN: Run/Stop, Ext1/2 Select or Run Enable. 38 FLN REF1 SRC Indicates if FLN is the source for speed reference 1 (1 = YES, 0 = NO). 39 FLN REF2 SRC Indicates if FLN is the source for speed reference 2 (1 = YES, 0 = NO).
FLN Detailed Point Descriptions Point Description Drive Parameter 50 PRC PID GAIN Sets the proportional gain of the active Process PID set, as selected by Point 54, PRC PID SEL (1 = SET2, 0 = SET1). 4001 (SET1) 4101 (SET2) 51 PRC PID ITIM Sets the integration time of the active Process PID set, as selected by Point 54, PRC PID SEL (1 = SET2, 0 = SET1).
FLN Detailed Point Descriptions Point Drive Parameter Description 69 FLN LOC REF Commanded by FLN to temporarily “steal” input reference control of the drive from its normal source and place it under FLN control. This functionality is analogous to placing the drive in HAND mode at the panel, with the reference control being taken by FLN instead. HAND mode at the panel has priority over this point.
FLN Detailed Point Descriptions Point Description 94 RESET FAULT Command by FLN to reset a faulted drive (1 = RESET, 0 = NO). Parameter 1604 must be set to COMM for FLN to control this state. The control input is rising-edge sensitive, so, once the command is issued, this point automatically returns to its inactive state. This “momentary” operation avoids any need for an explicit command to clear the point before a subsequent reset can be issued.
3AFE68320658 REV D / EN EFFECTIVE: 31.05.2007 © 2007 ABB Oy. All rights reserved. ABB Oy AC Drives P.O. Box 184 FIN-00381 HELSINKI FINLAND Telephone +358 10 22 11 Fax +358 10 22 22681 Internet http://www.abb.com/motors&drives ABB Inc.
