WI-GTWY-9-xxx Wireless Gateway V1.18
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The RSSI registers can be read by the host device, or mapped to I/O registers in other WI-
GTWY-9-xxx modules.
The first half of the register (8 most significant bits) will be decimal 0 (hex 00) if the remote
module has active communications. If a comms fail status to this address occurs, the most
significant bit will be set. For example, if the last message received from #38 is –99dBm, then
the 16 bit value of register 4438 will be decimal 99 or hex 0063. If the “comms fail” status for
#38 is set, the 16 bit value of register 4438 will become decimal 32,867 (32768 + 99) or hex
8063.
2.5.2
Repeaters
Radio paths may be extended by using intermediate modules as repeaters. A repeater will
receive and re-transmit the radio message. Up to five repeater addresses can be configured -
that is, a radio message can pass through five intermediate modules. For normal I/O messages,
any WI-I/O 9-x module (except WI-I/O 9-x-K modules) can be used as a repeater, however for
block read/write messages, only WI-GTWY-9-xxx modules can act as repeaters.
2.6
Radio Comms Failure
The WI-GTWY-9-xxx has an internal "communications failure" (comms fail) status for each I/O
point in its database. There is also a comms fail status for each module with direct
communications - see 2.5.1 above.
For I/O registers which are mapped to a remote output or another WI-GTWY-9-xxx, the comms
fail status is set if the WI-GTWY-9-xxx does not receive an acknowledgment for a message
being sent to that remote output. The comms fail status resets when a successful transmission
occurs.
For I/O registers which have been mapped , from a remote input or another WI-GTWY-9-xxx, a
comms fail time period may be configured. If a radio message for this I/O register has not been
received within this time, then this registers comms fail status is set. The comms fail status will
reset when a message is received for this register. If the comms fail time is configured as zero,
then the comms fail status will never be activated. Registers can be configured to reset (go back
to a value of zero) on comms fail.
The communications failure status is bit 15 of the status register for each I/O point. If the host
device reads a register as a digital or binary value, then the WI-GTWY-9-xxx returns bit 15 of
the register (0 or 1) - this is the comms fail bit of a status register.
It is important to use the comms fail status in the overall system design, as any system can fail.
The WI-GTWY-9-xxx also provides an additional comms failure feature to stop the WI-GTWY-
9-xxx transmitting output messages to an individual remote address if the WI-GTWY-9-xxx
already knows that this remote address is in communication failure. This prevents the WI-
GTWY-9-xxx from congesting the radio channel with a lot of unnecessary transmissions (and re-
transmissions). This function is called "Don’t Send if In Comm Fail" and is configurable by the
user for each individual remote address. The WI-GTWY-9-xxx retains a "remote address comms
fail" status for the remote addresses configured for this function. If any output with this remote