<5. Others (Converter)>
5-14
IM 12A01F01-03EN 2nd Edition : Feb. 19, 2019-00
5.2
Search Modbus
When the connection gets lost if, for example, you remove the connection cable to conduct
maintenance or calibration of the product on other premises but not yours, you can search
Modbus Device Address to communicate with SENCOM SA connecting to FLXA 402.
NOTE
Each device on the Modbus network requires a unique Device Address/Slave ID, usually
programmable for 1-247 devices. Therefore, each SENCOM SA must have different Device
Address from each other. This allows devices on the network to know what data packets are
relevant to them, and which are meant for other devices.
If Device Address/Slave ID 248 (invalid) is assigned, this function is disabled.
NOTE
For analog sensor module or Optical DO sensor, this function is not available.
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How to search Modbus
The next figure shows an example of Modbus search under the following condition.
●
Connect 3 SENCOM SAs of Modbus address 1, 3, 4
●
On the converter, address “1” is assigned to Address CH (sensor connection number)1-1,
“4” to 1-2, “12” to 1-3, “248 (invalid)” to 1-3.
(1) Select a sensor module. (in the sample, Sensor 1 is selected.)
(2) Modbus search is displayed. You can configure the address to start the search. After the
configuration and confirmation, tap “Start” to start the search Modbus.
Ch number (a number after “-”) of Address CH (sensor connection number)
and Modbus
address (1 to 247) are displayed.
<Example>
Modbus address assigned to Target sensor 1-2 is displayed on Sensor1 Ch2.
If the connection fails although the Modbus address is assigned valid (1 to 247), alert
shows up next to Ch number.
In the example, Modbus address 1, 4, are assigned to Target sensor 1-1, 1-2
respectively. This means the communication is established already. However, although
Modbus address 12 is assigned to 1-3, shows up because SENCOM SA of Modbus
address 12 cannot be found.
To start the search from the address 1, tap “Start”.
(3) “Searching” and the address are displayed.
If you tap “Cancel” while the address is still on search, the Modbus search stops and moves
to the screen for selecting sensor module.
(4) When Modbus address is found, a dialog box appears.
If you keep on searching, tap “YES”, then you will move to the screen for searching the
Modbus address.
Tap “Cancel” to stop the searching and move to the first screen for selecting sensor module.
(5) After you complete searching all valid Modbus address (1 to 247), a dialog box appears to
notify no more address is found.
