Request ID

A unique number representing this request. The server sends this ID with all responses. The client, upon receiving the response from the server can then associate it back with the request they made. This is important if the client is making multiple requests so it then knows what response is related to what request

The "key" Parameter

You will notice that the "key" parameter is the first parameter in each of the cht functions.

On the SC side, each chart you wish to access needs to have the "T29 SC-dX" study added to it. In the study settings is a field called "Key". You can set this "key" to anything that makes sense. The only requirement is that it is unique and you don't use the same "key" on two different charts.

The "key" parameter ties the excel function with a specific chart.

Case does matter - if you set a key "XYZ" (upper case) in Sierra Chart, the key in Excel must also be "XYZ" ("xyz" lower case won't work).