How to write data in an ION Meter configured as a Modbus Slave



End user would like to write data to any ION Meter that is configured as a modbus slave
Product Line:
ION75X0 RTU, ION8800, ION8600, ION8650 ION7550/ION7650, ION7300, ION8500, ION8400, ION8300, ION7500/ION7600
Modbus Communications
The ION meter configured as Modbus slave can easily provide data to its master using Modbus slave modules. It doesn't make any difference if the master is another ION meter (using "Modbus Master Device" modules) or a third party product. This articles detail the actions for the slave ION meter to receive information from the master.
ION Modules offer the availability for a slave meter to accept inputs. To do so, create External Pulse, External Boolean or External Numeric modules, depending on the type of information you need to import. All these "External" modules are available over Modbus. The map is given in the "Common_Modbus_Registers.pdf", starting on page 27. These modules can be modified over Modbus the same way as in a Vista diagram.
For example, to trigger the "External Pulse #1", write the number "1" at the Modbus address 42001.
To change the value of the "External Boolean #1", the address is 42201. Write "0" to turn to OFF state, and write "1" to turn to ON state.
To write a value in "External Numeric #1", simply write a value at the Modbus registers 42301 and 42302. The number needs to be in Signed Integer 32-bits format (42301 is the high order word, 42302 the low order word).
Note: Standard Security must be disabled for changes be made to the meter. If Standard Security is enabled, a "Modbus Exception # 3 - Illegal Data" message will be received when trying to write the register.

Note: The ION 6200 doesn't include ION modules. For Modbus communication with an ION 6200 refer to the "ION6200 Registers.pdf" attached below

For more information on the topics discussed in this afticle please take a look at the "Modbus and ION Technology.pdg" attached to this FAQ.