ProSoft MVI69E-MBS - Event Command Blocks (1000 to 1255, 2000 to 2255)

MVI69E-MBS ♦ CompactLogix Platform Reference
Modbus Serial Enhanced Communication Module User Manual
ProSoft Technology, Inc. Page 125 of 154
June 28, 2017
7.4.1 Event Command Blocks (1000 to 1255, 2000 to 2255)
Blocks 1000 to 1255: Event Port 1
Blocks 2000 to 2255: Event Port 2
Event Command blocks send Modbus commands directly from the ladder logic to
one of the Master ports. The Event Command is added to the high-priority queue
and interrupts normal polling so that this special command can be sent as soon
as possible.
Note: Overusing Event Commands may substantially slow or totally disrupt normal polling. Use
Event Commands sparingly. Event Commands are meant to be used as one-shot commands
triggered by special circumstances or uncommon events.
Blocks 1000 to 1255 or 2000 to 2255: Request from Processor to Module
Offset
Description
0
Write Block ID: 1000 to 1255 for a Port 1 command or 2000 to 2255 for a Port 2
command. The last 3 digits of the command specify the slave address to use for the
command.
1
Internal address in the module to be used with the command.
2
Count parameter that determines the number of digital points or registers to associate
with the command.
3
Swap type for the data.
4
Modbus Function Code to be associated with the command.
5
Modbus address in the slave device to be used in the command.
6 to (n-1)
Spare
Where n = 60, 120, or 240 depending on the Block Transfer Size parameter.
Blocks 1000 to 1255 or 2000 to 2255: Response from Module to Processor
Offset
Description
0
Read Block ID: 1000 to 1255 or 2000 to 2255 requested by the processor.
1
Write Block ID: To be used by the processor in its next Write block
2
Result of the event request. 1 = the command was placed in the command queue; 0 =
no room was found in the command queue.
3
Number of commands in the command queue for the specified port.
4 to (n-1)
Spare