AEG 239 D User Manual download pdf (Page 16)

CG–12 239 MOTOR PROTECTION RELAY – COMMUNICATIONS GUIDE

COMMUNICATIONS GUIDE

CG.4 16: Performing Commands

Some PLCs may not support execution of commands using function code 5 but do

support storing multiple setpoints using function code 16. To perform this operation

using function code 16 (10H), a certain sequence of commands must be written at the

same time to the 239. The sequence consists of: Command Function register,

Command operation register and Command Data (if required). The Command

Function register must be written with the value of 5 indicating an execute operation

is requested. The Command Operation register must then be written with a valid

command operation number from the list of commands shown in the memory map.

The Command Data registers must be written with valid data if the command

operation requires data. The selected command will execute immediately upon

receipt of a valid transmission.

MESSAGE FORMAT AND EXAMPLE

Master Transmission Bytes Example (hex)

SLAVE ADDRESS - 1 byte 11 message for slave 11

FUNCTION CODE - 1 byte 10 store Setpoints

DATA STARTING ADDRESS - 2 bytes 00 80 Setpoint address 0080

NUMBER OF SETPOINTS - 2 bytes 00 02 2 Setpoints (4 bytes

total)

BYTE COUNT - 1 byte 04 4 bytes of data

DATA 1 - 2 bytes 00 05 data for address 0080

DATA 2 - 2 bytes 00 01 data for address 0081

CRC - 2 bytes 7E CE CRC calculated by the

master

Slave Response

SLAVE ADDRESS - 1 byte 11 message from slave 11

FUNCTION CODE - 1 byte 10 store Setpoints

DATA STARTING ADDRESS - 2 bytes 00 Setpoint address 0080

NUMBER OF SETPOINTS - 2 bytes 00 02 2 Setpoints

CRC - 2 bytes 42 B0 CRC calculated by slave

1 2 ... 11 12 13 14 15 16 17 18 19 20 21 ... 57 58

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AEG 239 D User Manual Page 16