User manual

105G Wireless Gateway User Manual
Elpro_man_105g_1.18.doc Page 16
The 105G also transmits periodic update messages if there has been no change - if an I/O register
is mapped to a remote output or another 105G, then that register can be configured with an
update time.
105G modules can transmit to 105G modules as well as other 105G modules. There can be
multiple 105G 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 are able to communicate with each other - for example, a.
Modbus 105G can communicate with an Ethernet 105G. Data can be sent from one to the other
by using “mappings” which essentially link I/O registers from one 105G to I/O registers on
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
♦ real time clock, or
♦ on demand by the host device, by writing to a “trigger register” in the 105G.
Block Write Message
A block write message transmits a consecutive block of register values from one 105G to a
destination 105G. It can be triggered by: