Teracom TCW242-S, Руководство пользователя

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TCW242-S_R1.0 – July 2021 Page 13
decreases the time until the sensor stops responding. In order for the operation sustainability,
the found time should be increased with for example 20%.
8.2.2.2. Modbus RTU sensors
This section allows you to add, delete or edit MODBUS RTU sensors/registers. All these are
primary parameters and can be used in forming channels.
It is recommended to add sensors/registers one by one using the scan tool described in
8.2.2.1.
Up to 24 sensors/registers can be added. All they are shown in the table.
According to the MODBUS convention, possible addresses for sensors are in the range of 1 to
247.
The Multiplier and Offset works as follows:
Value = (Raw_Value * Multiplier) + Offset.
If you want to see the raw value of the sensor/register set Multiplier=1 and Offset=0.
During operation, all sensors are polled consecutively. The controller expects an answer in
"response time-out". If the sensor does not respond for that time, the controller addresses
the next sensor. If the same sensor does not respond in series 3 times, the device assumes
that it is not present in the system but continues to polls it.
According to the above paragraph, special attention should be paid to response time-out. On
the one hand, the time-out should be large enough for the sensor to respond, but on the
other hand, the sum of all sensor time-outs forms the "maximum response time-out" of the
whole system. The "maximum response time-out" determines the response of the system.
For the sustainable system operation, polling of every sensor is made at a fixed time - "Polling
time". It is user-selectable and can be 1, 2, 3, or 4 seconds. By default, it is 1 second.
It is recommended that "Polling time" ≥ "Maximum response time-out".