Datasheet

ManualsBrandsVOLTCRAFT ManualsLaboratory & Bench PSUsPSP 12010, 200W 1 Output Programmable DC Power Supply, Switched Mode, Bench

Ideal Start 1 0 0 0 1 1 0 Stop Ideal

Communication Protocol for Programmable Power Supply

PSP 1405/12010/1803 use following protocol while communicating with PC through

RS232 Serial port

Baud rate: 2400 Bits / Second

Port: COM1

Parity: None

Data Length: 8 Bits

Stop Bit: 1

To transmit any byte from the PC there will be one high level state indicating start bit

followed by bit pattern of the data byte from LSB to MSB and a Low-level stop bit.

For Example to transit 61H(0110001-Binary) the pattern will be as shown below.

This is to be noted that RS232 has negative logic levels. That is Low or negative for 1,

High or Positive for 0 and Ideal state is low or negative.

Communication Frame

VSP series communicates in a fixed length frame. Each communication frame has three

bytes. The first byte is the command followed by the two data bytes. Frame remains three

bytes even if command does not have any data. Command formats are given below.

Command Format

1.Set Voltage:

(AAh) (V1) (V2)

This sets output voltage to given value

V1 - Higher byte (Only lower 4 bit will be considered)

V2 - Lower byte

Example: To set Voltage to 40.00 it will be (FA0)H and the command will be

AA0FA0H.

Summary of content (4 pages)

PAGE 1
Communication Protocol for Programmable Power Supply PSP 1405/12010/1803 use following protocol while communicating with PC through RS232 Serial port Baud rate: Port: Parity: Data Length: Stop Bit: 2400 Bits / Second COM1 None 8 Bits 1 To transmit any byte from the PC there will be one high level state indicating start bit followed by bit pattern of the data byte from LSB to MSB and a Low-level stop bit. For Example to transit 61H(0110001-Binary) the pattern will be as shown below.
PAGE 2
.Set Output Relay ON/OFF: (ABh) (S) (R) This sets output voltage to given value S 1: Set Relay to ON 0: Set Relay to OFF R Reserved (Keep it to 0h) Example: To set output relay ON command will be AB0100H 3.Set Imax: (ACh) (I1) (I2) This sets Imax to given value I1 Higher byte (Only lower 4 bit will be considered) I2 Lower byte Imax can be in the range of 0-500 i.e. 0 –1F4h Example: To set Imax to 5.00 Amp the command will be AC01F4H. 4.
PAGE 3
8.Read Thermal Status: (B1h) (0) (0) This command asks the Power supply to return the Thermal Status of the Power Supply. Return: (B1)(S)(0) S 1 for Thermal Protection ON 0 for Thermal Protection OFF Example: To read the thermal status the command will be B100000H. Unit will return B10100H for Thermal protection ON. 9.Read Device ID: (B2h) (0) (0) This command asks unit to send the device ID Returns: (B2h)(ID)(Ver) ID: 1 for PSP 1405 2 for PSP 12010 3 for PSP 1803 Ver: Software Version 0 for Version 0.
PAGE 4
Communication Establishment method : To establish the communication between computer and unit we have a loop in our computer program which requests device ID continuously and when ever it receives the Device ID from unit, computer understands the device Model and handles the data accordingly. This makes sure that both computer and unit are ready to communicate and synchronization is completed.