Allen-Bradley micrologix 1500 Reference Manual

Publication 1762-RM001C-EN-P
21-4 Communications Instructions
The Message File
The MSG instruction built into the controller uses a MG data file to
process the message instruction. The MG data file, shown at left, is
accessed using the MG prefix. Each message instruction utilizes an
element within a MG data file. For example, MG11:0 is the first element in
message data file 11.
Message File Sub-Elements
Each MSG instruction must use a unique Element in a MSG File. The MSG
element for each MSG instruction holds all of the parameters and status
information for that particular MSG instruction.
Each MSG File Element consists of Sub-Elements 0 through 24 as shown
in the following table.
Message File Element
Sub-
Element
Name Description Parameter Size User Program
Access
(1)
0 to 2 Reserved Word read only
3 bits 07-00: CMD code, bits 15-08: FNC code derived Word read only
4 Reserved Word read only
5 MG11:0.RBL Remote Bridge Link ID Y Word read only
6 MG11:0.LBN Local Bridge Node Address Y Word read only
7 MG11:0.RBN Remote Bridge Node Address Y Word read only
8 MG11:0.CHN Channel - 0 (channel 0)
Always 0 for MicroLogix 1200 Controllers and MicroLogix 1500
1764-LSP Processors
Y Word read only
8 MG11:0.CHN Channel - 0 (channel 0) or 1 (channel 1)
MicroLogix 1500 1764-LRP Processors
Y Word read/write
9 MG11:0.NOD Target Node Number Y Word read/write
10 MG11:0.MTO Message timeout setting or preset in seconds Y Word read/write
11 Reserved Word read only
12 Target Location information (See tables on page 21-5 for options) Y Word read only
13 MG11:0.TFN Y Word read/write
14 MG11:0.ELE Y Word read/write
15 Y Word read only
16 Control bits (See Control Bits table on page 21-5 for details) N 16-bits read/write
17 Status bits and Range parameter (See table on page 21-6 for details) Mixed 16-bits read only
18 MG11:0.ERR Error code (See Error Codes on page 21-21) N Word read only
19 Time since message started in seconds N Word read only
20 Reserved Word read only
21 Internal message start time in seconds N Word read only
22 to 24 Reserved N Word read only
(1) User access refers to user program access (MSG File word or bit used as an operand for an instruction in a ladder program) or access via Comms while in any mode other
than download (via Programming Software or Memory Module).

Allen-Bradley micrologix 1500 Specifications

General

Brand	Allen-Bradley
Model	micrologix 1500
Category	Controller
Language	English