Chapter One Introduction
MAN_105G_1.5 Page 12
105G modules can transmit to 105G modules as well as other 105G modules. There can be
multiple 105G and 105C modules in a network - as well as 105U I/O. Because the 105U
protocol is peer-to-peer, there are few constraints on communications between multiple 105U
modules.
Poll Messages
A 105G can also generate poll messages to remote 105U modules. These poll messages act in
the same way as a start-up poll - the remote module immediately responds with update
messages for any I/O mappings configured to the 105G.
Poll messages can be triggered by:
♦ time period, configurable 1 – 4096 sec (1.1 hour), or
♦ real time clock, or
♦ on demand by the host device, by writing to a “trigger register” in the 105G
1.3.2 105G to 105G Network
Different types of 105G modules can communicate - for example, a Modbus 105G can
communicate with an Ethernet 105G. I/O registers in one 105G can be transmitted to I/O
registers in another 105G. When the 105G is configured, “mappings” can be entered linking
I/O registers to registers in another 105G.
As well as the normal “I/O change” messages and update messages, the 105G has “block
read” and “block write” messages for use with other 105G modules. These messages will
transmit multiple register values instead of only one as in the normal 105U message. The
block read/write messages increase the efficiency of radio communications where a 105G
“sees” a large number of changes in its database at the one time. For example, if a host writes
a block of 100 signal values to a 105G, and 20 of these values have changed since the last
write-operation. If the block is mapped to another 105G, then the 105G can transmit all 20
values in one radio message, instead of 20 messages.
Normal I/O messages can be repeated by any type of 105U I/O module, however block
read/write messages can only be repeated by other 105G modules.
Block Read Message
A block read message is a request to another 105G to transmit the values of a consecutive
block of registers. The destination 105G will respond with the values, which will be stored in
a corresponding block of registers in the originating 105G. A block read message can be
triggered by:
♦ time period, configurable 1 – 4096 sec (1.1 hour), or
105U-G
105U-3
105U-1
PLC
105U-C
PLC
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