Installing Modbus

I am trying to get tags from a device that only uses serial communication through RS232 ,to get tags to ignition , anybody knows how to do that .

Ignition's modbus driver can do that, via serial port on the Ignition gateway, though it is most robust to use a Serial-to-Ethernet converter and configure Ignition to use Modbus RTU over TCP.

I recommend the Moxa family of devices for use with my alternate driver, and offer Moxa configuration advice in the user manual. That advice applies to IA's driver, too.

Slight correction - it's best to use a Modbus TCP gateway that converts Modbus RTU to Modbus TCP, and then to use the standard Modbus TCP driver. Moxa makes both serial to ethernet converters and Modbus TCP gateways.

thanks for reply , you mean to use converter serial/ethernet and connect from the device to plc or just that converter without plc and ignition will find it .i know little about Modbus , i know its master/slave messaging .

My go-to is the Moxa MB3170, DIN rail mount, 2 power inputs, RS232 and 485, two RJ45 ports.

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The Moxa 5000 series NPort devices are dramatically cheaper port-for-port, and can have many more ports. For single-client (Ignition) applications, I'll take the NPort products almost every time. (The exception is when using the IA driver in a redundant pair.)

Yeah, but you said robust, not cheap. The hack that it is putting Modbus RTU directly onto TCP can't reasonably be called robust...

We'll have to agree to disagree. Setting the Moxas to buffer properly for Modbus (they don't, out of the box, which is why I have an appendix for that) makes packet assembly and delivery exceedingly robust. As long as the driver enforces Modbus packet timing rules, it'll recover from network hiccups remarkably cleanly.