Omron GRT1 - 27-11-2006 Operation Manual page 103

Explicit Messages
C-3 Using Explicit Messages
The following example shows how to use explicit messages with a PROFIBUS Communication Unit connected
to a CJ1W-PRM21 Profibus Master Unit.
Example: Sending a "Unit Maintenance Present Value Read" command to the
Example: PROFIBUS Master Unit's station address: 05
Unit number: 0
Unit address: 11 Hex
GRT1-PRT Communication Unit's station address: 65
PROFIBUS DP-V1 Master Unit
Operation
Reads the Alarm data of the connected SmartSlice I/O Unit from the PROFIBUS Communication Unit.
The data is read using the EXPLICIT MESSAGE SEND command (2801).
The command data is written in words starting from D01000 in the PLC and the response data is stored in
words starting from D02000.
If the command does not end normally, the end code is stored in D00006 and the send command is re-exe-
cuted.
Note The maximum length of the EXPLICIT MESSAGE SEND command (2801) when used for sending data
over PROFIBUS is limited to 1004 bytes.
84
Ladder program
Read SmartSlice
alarm data
SmartSlice I/O System
PROFIBUS Communication Unit
Explicit message
CMND
sent
C
S
D
PROFIBUS
Network
Appendix C
.