Ignition - How to Ping a Siemens Remote I/O in Ignition SCADA Gateway (When It's Not an OPC Device)

Introduction

In many industrial installations, Siemens Remote I/O modules like ET 200SP are used alongside S7-1200 PLCs to extend digital or analog input/output capabilities closer to the field. These Remote I/Os communicate directly with the main PLC, which is typically the only device added to SCADA, in this case Ignition, via OPC UA.

But what if you want to monitor whether a Remote I/O is powered or connected and it’s not directly accessible via OPC?

In this post, I’ll show how you can use a simple gateway ping script in Ignition to monitor the connectivity status of your Siemens Remote I/O device and update a memory tag that reflects whether the I/O is reachable on the network.

Network Setup Overview

In my setup:

A Siemens S7-1200 PLC is connected to the Ignition SCADA server through a managed switch.
A Siemens Remote I/O (ET 200SP) communicates only with the S7-1200, not directly with SCADA.
The Remote I/O cannot be added as a device in Ignition’s OPC device list.
Therefore, ping is used to check whether the Remote I/O is online (i.e., powered and network-connected).

Since Remote I/Os are not directly visible to Ignition:

You can’t use OPC browsing or diagnostics.
But most Siemens Remote I/Os respond to ICMP ping, which lets you check if they’re powered and connected.
A successful ping = I/O is likely online.
No reply = I/O is offline or disconnected.

Ignition Gateway Script (Every 15 Seconds)

This gateway timer script runs every 15 seconds to ping the Remote I/O’s IP and update a Boolean memory tag (ET-200SP) in Ignition:

The gateway script

Unreachable ping response set the tag status to false

Valid ping response set the connection status to true

subprocess python module the program to run system commands as if they were typed in the terminal or Command Prompt.

Trigger Frequency: Set this script in Gateway Event Scripts > Timer Scripts and run it every 15 seconds.

import subprocess

ip_address = "192.168.12.41"
tag_path = "[default]ET-200SP"

try:
    # Run the ping command and capture output
    process = subprocess.Popen(["ping", "-n", "1", ip_address], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    output, error = process.communicate()

    # Convert output to a string
    output_str = output.decode("utf-8")

    # Check if teh reply is valid
    if "Reply from" in output_str and "Destination host unreachable" not in output_str:
        status = True  # ET-200SP is online
    else:
        status = False  # ET-200SP is offline

except Exception as e:
	system.util.getLogger("PingCheck").error("Ping Error for {}: {}".format(ip_address, str(e)))
	status = False  # Assume ET-200SP is offline if an error occurs

# Write the status of ET-200SP to the tag
system.tag.writeBlocking([tag_path], [status])

Conclusion

This method is a lightweight workaround for monitoring non-OPC devices in your SCADA network. While ping doesn't confirm full device health, it’s sufficient for basic connectivity checks and enhances system visibility.