TD9300 Installation and Configuration Manual
49
© Tait International Limited September 2018
5.2.9
Call Management
Time
synchronisation
interval
The duration at which the TD9300 performs a time/date synchronisation
with the SCADA Gateway, this happens asynchronously to any SCADA
traffic.
Queue message
timeout
The amount of time that an outgoing message to the SCADA Gateway can
remain in the TD9300 message queue before being automatically dropped.
Response delay
This is the maximum time the data terminal will wait for data from the
RTU.
If there is no data from the RTU in this time then it assumes there is no more
data to send and floor control is passed back to the SCADA Gateway. The
default response delay is set to 500ms.
A non-optimal setting will have a negative impact on system throughput. If
the value is too short, SCADA transactions will be split over multiple DMR
radio calls. If the value is too large, the DMR call will be held up longer
than it needs to be at the end of the SCADA transaction. A value that is too
small will have a larger impact, so it is better to err slightly on the large side
for this setting. For serial-connected RTUs this setting needs to take into
account the possible packet serialization latency over the serial line (both
to and from the RTU) plus any processing delay expected in the RTU. We
recommend tuning this value on the bench when initially integrating with
an RTU.
Receive timeout
This is the maximum time the data terminal should wait for a response from
the gateway before closing the current call.
The default value is 15 seconds. This timeout is used only if something
goes wrong with the communications between the SCADA Gateway and
the data terminal. In most cases the default value is acceptable.
Inactivity timeout
This is how long to wait before power cycling the radio if no internal
communications have been received from the radio in the data terminal.
Status NACK retry
interval
This is the delay (in milliseconds) between sending status messages if a
status message fails to be sent (request is rejected) by the radio.
Outgoing data call
enable
When enabled, the TD9300 is able to generate a data call directly to the
SCADA Gateway to send unsolicited traffic.
When disabled, if the TD9300 has unsolicited traffic to send, it sends a
callback status call to the SCADA Gateway and waits for an incoming data
call.