The operator may see a Wonderware InTouch Memory Message value in the HMI while the corresponding Ignition tag remains unavailable. Treat that as an interface problem first: determine whether InTouch exposes the value as a readable item, then choose an OPC bridge or redirect the value to a PLC tag.
Can InTouch expose this message as a readable item?
First identify the exact InTouch object and its current value. A displayed message is not automatically a browseable OPC item: the HMI display, the InTouch data item, and an Ignition tag are separate layers. Record the message’s InTouch name, value, and update behavior, then check whether the configured data-access path can browse and read that item.
| Reading or check | What it tells you | Next step |
|---|---|---|
| InTouch value changes as expected | The source value exists at the HMI layer. | Check whether the same item is exposed to the selected OPC server. |
| Item is browseable and readable through the OPC path | The source can be addressed outside the HMI display. | Configure the Ignition-side connection and tag. |
| Item is not browseable or has no readable value | The failure is upstream of Ignition tag binding; the chosen access path does not expose the item. | Check the InTouch/OPC configuration or use a PLC-tag redirect. |
Which data path fits the number of values?
For a few values, redirecting the Memory Message to a PLC tag is a practical path. The PLC becomes the handoff point: InTouch writes or redirects the value there, and Ignition reads the PLC tag through its existing PLC data connection. This avoids introducing an InTouch-to-OPC connection solely for a small number of items.
For a broader set of InTouch data, evaluate an OPC path. The described architecture uses FSGateway (or OI Gateway in newer versions) to expose InTouch tags through OPC, then connects Ignition using its OPC-COM Module. Confirm the installed gateway and Ignition module support the intended protocol and item types before committing to this design. OI Gateway OPC UA capability was mentioned as a possible newer-version option; confirm that capability and configuration in the installed release rather than relying on a general version assumption.
| Option | Where to configure | Effect |
|---|---|---|
| Redirect to PLC tag | InTouch message redirection and PLC tag; Ignition’s existing PLC connection | Adds a PLC-mediated handoff; suitable when only a small number of values are needed. |
| FSGateway / OI Gateway OPC path | InTouch data exposure, gateway item access, and Ignition OPC connection | Provides a direct data-access path from InTouch-exposed items to Ignition. |
Does the failure belong to the source, gateway, or Ignition binding?
Follow the value across each boundary, using the same item name and a known changing value where possible. A good display value does not prove that the gateway exposes it; a browsed OPC item does not prove that Ignition’s tag is bound to the correct item.
- Read the value in InTouch. If it is wrong or static there, troubleshoot the source object or its update logic before changing Ignition.
- Browse or read the item through the selected gateway. If it is absent or incorrect, resolve the InTouch exposure, item naming, or gateway configuration before editing the Ignition tag.
- Read the same item from Ignition’s OPC connection. If the gateway shows the value but Ignition does not, inspect the connection state, selected server, and item binding.
- For a PLC redirect, monitor the destination PLC tag before checking the Ignition tag. If the PLC value is wrong, investigate the redirect or PLC-side mapping; if it is correct, continue to the Ignition binding.
This staged check localizes the fault: a source-value problem is different from an item-exposure problem, and both differ from a bad Ignition binding. Change one layer at a time so a corrected value identifies the resolving boundary.
How do you configure the selected path?
For the PLC route, configure the InTouch redirection to the intended PLC tag, then verify that Ignition already has access to that tag. For the OPC route, configure the gateway to expose the required InTouch item, then create the Ignition connection and bind the tag to the gateway item. Exact menus and item syntax depend on installed product versions and the configured gateway; read them from those products rather than guessing.
- Choose either PLC redirection or OPC access and document the source item and destination item names.
- Configure the handoff at the source or gateway, then independently confirm the destination item is readable at that layer.
- In Ignition, create or update the tag using the exact item exposed by the selected connection.
- Compare the Ignition value with the source or intermediate value while that value changes.
What confirms the value is crossing the full path?
Verify behavior, not just a successful browse or a single matching snapshot. Change the source value through its normal operating mechanism and observe it at each boundary: InTouch, gateway or PLC tag, then Ignition. Confirm that Ignition follows the change and that the chosen representation is usable by the consuming logic or display.
If the source changes but an intermediate value does not, return to that handoff. If the intermediate value changes but Ignition does not, recheck the Ignition connection and item binding. Keep the path under observation long enough to see normal updates, and repeat with representative values used by the application.
Frequently asked questions
How do I get an InTouch Memory Message into Ignition?
Expose the InTouch item through an OPC gateway and connect Ignition with the applicable OPC module, or redirect the value to a PLC tag and read it through Ignition’s PLC connection. For only a few values, the PLC redirect can be the simpler handoff.
How do I tell whether the problem is an Ignition tag binding?
Read the item at the gateway or PLC destination first. If it is correct there but wrong or unavailable in Ignition, check the selected connection and the exact item binding.
Can FSGateway expose InTouch tags to Ignition?
FSGateway was proposed as an OPC bridge, with Ignition connecting through its OPC-COM Module. Verify that the installed gateway and Ignition versions expose and support the specific item you need.
How do I choose between OPC and redirecting to a PLC tag?
Use a PLC redirect when only a small number of values need to cross and the PLC path is already available. Evaluate the OPC gateway path when you need to expose InTouch items more broadly, and verify item access before binding Ignition tags.
How do I verify an InTouch value reached Ignition?
Change the source value and compare it at InTouch, the gateway or PLC destination, and the Ignition tag. The final verification step is confirming that the Ignition tag follows the source change through the complete selected path.