Read/write tag values from/to a REST API server

Hi Folks,

I’m a total newbie to Postman, so please forgive my mistakes and inevitable formatting inadequacies. I have searched the website, but I don’t think anyone else has had to ask such a basic question as this.

I’m using Postman to test responses to/from a REST API server provided by a product called Kepware. I can find no mention of Kepware anywhere on this site, but that may not matter. What I’m asking concerns the JSON call/response values.

The Kepware server is configured so that the REST API agent is pointing to a tag with the name “Channel1.Device1.Order”, which is of type string.

The REST API agent URL is “”.

I tried making a POST request to the REST API server (URL link ) using this JSON body script:

[ { “id”: “Channel1.Device1.Order”, “v”: “000000717087” } ]

The intention was to write the value “000000717087” into the tag; and the actual script content came from an example in the Kepware manual.

Postman returned this JSON response, along with a status 200:

{ “writeResults”: [ { “id”: “Channel1.Device1.Order”, “s”: true, “r”: “” } ] }

According to the manual, this response indicates that the tag value was successfully updated.

Now I want to read the same tag, but I have no example script. So I tried this:


Postman response (with status 200):

{ “readResults”: }

No errors, but no value either. Is my GET request incorrectly formatted? Or do you think the tag wasn’t successfully updated in the first place?


John M.