Weidmuller WI-GTWY-9 User Manual page 17

WI-GTWY-9-xxx Wireless Gateway
WI-GTWY-9-xxx "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 WI-GTWY-9-xxx, and 20 of these
values have changed since the last write-operation. If the block is mapped to another WI-
GTWY-9-xxx, then the WI-GTWY-9-xxx can transmit all 20 values in one radio message,
instead of 20 messages.
Normal I/O messages can be repeated by any type of WI-I/O 9-x I/O module, however block
read/write messages can only be repeated by other WI-GTWY-9-xxx modules.
Block Read Message
A block read message is a request to another WI-GTWY-9-xxx to transmit the values of a
consecutive block of registers. The destination WI-GTWY-9-xxx will respond with the values,
which will be stored in a corresponding block of registers in the originating WI-GTWY-9-xxx.
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 WI-GTWY-9-xxx.
Block Write Message
A block write message transmits a consecutive block of register values from one WI-GTWY-9-
xxx to a destination WI-GTWY-9-xxx. It 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 WI-GTWY-9-xxx, or
♦ a change-of-state event occurring within the block of I/O registers.
If a block write message has been configured to be transmitted on change-of-state, a "time
window" is configured. When a change-of-state occurs in one of the registers in the block, the
time window will be activated. All changes during the time window will be grouped together
and transmitted as one block write message. That is, the block write message will not be sent
immediately the first change-of-state occurs (unless the time window is configured to zero), but
will be sent at the end of the time window - any other registers in the block that change during
the time window will be sent as part of the same message. The time window can be configured
from 0 – 255 seconds.
1.3.3 "Data Concentrator" Networks
WI-GTWY-9-xxx units can act as "data concentrator" units to collect I/O from a local network of
WI-I/O 9-x wireless I/O modules and pass the I/O on to another WI-GTWY-9-xxx as a block.
This type of network reduces the amount of radio traffic and is suitable for systems with a large
number of I/O modules. The system is divided into local sub-networks, each with a WI-GTWY-
9-xxx unit. The WI-I/O 9-x modules transmit their I/O vlaues to the WI-GTWY-9-xxx. The WI-
GTWY-9-xxx then transfers these values to the "central" WI-GTWY-9-xxx using a block
transfer which is very efficient compared to a lot of individual I/O transmissions.
User Manual V1.18
17