B&B Electronics GW-7553 - Manual - Manual (Page 45)

GW-7553 PROFIBUS/Modbus TCP Gateway User Manual (Version 1.00, Dec/2008) PAGE: 45
Table 14 Receive “0xFF” in the input data area
Module Byte Data type Representation Value
Input 0 Byte Hex 0xFF
Input module
Input 1 Byte Hex 0xFF
PS:
Modbus command:
Query message
DA FC
SA
(Hi)
SA
(Lo)
NO
(Hi)
NO
(Lo)
BC DATA
CRC
check
01 0F 00 00 00 10 02 FF FF E3 90
Response message
DA FC
SA
(Hi)
SA
(Lo)
NO
(Hi)
NO
(Lo)
CRC
check
01 0F 00 00 00 10 54 07
z DA: Device Address-0x01
z FC: Function Code-0x0F=>Write multi-DO
z SA(Hi): Start Address(Hi byte)-0x00
z SA(Lo): Start Address(Lo byte)-0x00
z NO(Hi): No. Of points (Hi byte)-0x00
z NO(Lo): No. Of points (Lo byte)-0x10
z BC: Byte Count-0x02
4.8.2 Receiving data from the PROFIBUS Master device
--Send Command to read DI of the GW-7553
The user needs to input command (” 01 02 00 00 00 10”) in MBRTU and
click button to send Modbus command: “01 02 00 00 00
10 79 C6” and then MBRTU can receive response message (” 01 02 02 00 00