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Reading MODBUS data using RouterOS

As of right nowthis moment, you can only read function code "3" output values. So if the connected MODBUS device can give a response to a Function Code 3 (read Analog Output Holding Registers) command → you can get/print it in the RouterOS terminal, like so:

[admin@device] > {:local output [/iot modbus read-holding-registers slave-id=0x03 num-regs=0x1 reg-addr=0x0 as-value once];:put [($output->"values")]}
2349
[admin@device] > {:local output [/iot modbus read-holding-registers slave-id=0x03 num-regs=0x5 reg-addr=0x0 as-value once];:put [($output->"values")]}
2353;3;500;75;38

Parameters that can vary are "reg-addr","num-regs" and "slave-id". All of them depend on what which values are supported by the MODBUS-connected device.

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