Allen-Bradley MicroLogix 1200 Reference Manual

Publication 1762-RM001C-EN-P
Communications Instructions 21-29
Local Messaging
Examples
Three examples of local messaging are shown in this section:
•
500CPU message type
•
485CIF message type
•
PLC5 message type
A summary of the message instruction configuration parameters is shown
below.
Parameter Description
This Controller Communication
Command
Specifies the type of message. Valid types are:
•
500CPU Read
•
500CPU Write
•
485CIF Read
•
485CIF Write
•
PLC5 Read
•
PLC5 Write
Data Table Address For a Read, this is the starting address which receives data.
Valid file types are B, T, C, R, N, and L.
For a Write, this is the starting address which is sent to the target device.
Valid file types are O, I, B, T, C, R, N, L, ST
(1)(2)
, and RTC
(1)(3)
.
Size in elements Defines the length of the message in elements.
•
1-word elements; valid size: 1 to 103.
•
2-word elements; valid size: 1 to 51.
•
8-word elements; valid size: 1
•
42-word elements; valid size 1 to 2
•
Timer (500CPU and 485CIF), Counter, and Control elements; valid size: 1 to 34.
•
PLC-5 Timer elements; valid size: 1 to 20
Channel Identifies the communication channel. Always Channel 0 (or Channel 1 for MicroLogix 1500
1764-LRP Processor only.)
Target Device Message Timeout Defines the amount of time the controller waits for the reply before the message errors. A
timeout of 0 seconds means that the controller waits indefinitely for a reply. Valid range is from
0 to 255 seconds.
Data Table Address
(500CPU and PLC5
message types)
For a Read, this is the address in the processor which is to return data.
Valid file types are S, B, T, C, R, N, and L.
For a Write, this is the address in the processor which receives data.
Valid file types are I, O, S, B, T, C, R, N, L, and RTC
(1)(3)
.
Data Table Offset
(485CIF message
types)
This is the word offset value in the common interface file (byte offset for PLC device) in the
target processor, which is to send the data.
Local Node Address Specifies the node number of the device that is receiving the message. Valid range is 0 to 31
for DH-485 protocol, 0 to 254 for DF1 protocol, or 0 to 63 for DeviceNet™.
Local/Remote Specifies whether the message is local or remote.
(1) Applies to MicroLogix 1200 Series B and later, and 1500 Series B and later.
(2) 485CIF write ST-to-485CIF only.
(3) 500CPU write RTC-to-Integer or RTC-to-RTC only.

Allen-Bradley MicroLogix 1200 Specifications

General

Brand	Allen-Bradley
Model	MicroLogix 1200
Category	Control Unit
Language	English