ProSoft Technology MVI69-MCM User Manual
Page 125
MVI69-MCM ♦ CompactLogix or MicroLogix Platform
Reference
Modbus Communication Module
User Manual
ProSoft Technology, Inc.
Page 125 of 167
March 22, 2011
Read Block - Read Slave Status
Offset
Description
Length (words)
0
3002 to 3006 or 3102 to 3106
1
1
Write Block ID
1
2 to 61
Slave Poll Status Data
60
62 to (n + 1)
Spare (if Block Transfer Size > 60)
(n - 62)
n= 120, or 240 depending on the Block Transfer Size parameter (refer to the
configuration file).
5.5.3 Event Command
Event Command blocks send MODBUS commands directly from the ladder logic
to one of the Master ports. The Event Command will be added to the high-priority
queue and will interrupt normal polling so that this special command can be sent
as soon as possible.
Note: Overuse of Event Commands may substantial 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.