Rockwell Automation 1771-DMC_DMC1_DMC4_DXPS Control Coprocessor User Manual - Manual (Page 67)

Chapter 5
Developing Programs
5-7
The control coprocessor can receive unsolicited messages from the PLC-5
programmable controller. Two types of messages are supported:
read data (word-range) from the control coprocessor
write data (word-range) to the control coprocessor
The control coprocessor supports up to 32 unsolicited messages. The
control-coprocessor message numbers are 0-31 (ASCII). Use the control-
coprocessor MSG library of commands with a directly connected PLC-5
programmable controller.
PLCĆ5 ProgrammableĆController MSG Instruction
A PLC-5 programmable controller uses the message (MSG) instruction for
unsolicited communication with the control coprocessor. You program the
MSG instruction in the ladder logic of the PLC-5 programmable controller.
This PLC-5 programmable-controller communication with the control
coprocessor is through the direct-connect mode side connector (Port 3A).
You specify a control-block address when you first enter the MSG
instruction. The programming terminal then automatically displays a
data-entry screen, where you enter instruction parameters that are stored at
the control-block address. You can also use the data-monitor screen to edit
selected parameters of the MSG instruction.
See the PLC-5 Programming Software Instruction Set Reference,
publication 6200-6.4.11, for more information on the message instruction.
PLC-5 Ladder-Logic Program
Enter the information in the PLC-5 programmable-controller message
control block. See Figure 5.1. Use only the choices listed:
communication commands—PLC-3 word-range read or PLC-3 word-
range write
destination data-table address—“00” through “31”
port number—3A
Important: On the 6200 Series Programming Software data-entry screen,
specify 3A for the communication port number. You must use the MG
data type for the control block if you want to set the port number.
How to Use Message
Instructions