Direct Modbus Write/Reads (HC900)

Ignition
, ,
1

TLDR:
I want to make direct Modbus Writes/Reads without using tags. Is this possible through scripting?

Details:
Using a Honeywell HC900-C50 Furnace Controller, I would like to be able to download new heat treat profile settings to a controller and verify that it is correct. This is outlined through this manual, on page 64 (56).

image
image796×733 130 KB

Each controller can support 99 profiles*, which to the layman should be enough, but the furnace guys want even more than 99. I have this idea that we designate a "dynamic" profile and update the dynamic profile's heat treatment details based on what part they are running.

Issue:
The profile can be up to 50 segments of 8 registers each. 400 registers per controller, and we have 6 of them, that's 2400 tags. That just seems like a lot of tags. I know there are ways to lessen the work: dynamic tags, UDTs ect; but I was wondering if there was a way to interact with the Modbus Module itself or do I need to use tags?

(*) This can be expanded to up to 1310 profiles, but they have issues keeping the profiles consistence across all furnaces, so Modbus reading question still stands. If anyone is using a HC900 Furnace Controller and finds this post, it's under the "Recipe", then "Allocate Recipe Memory" setting.

2

Yes, these scripting functions do not require tags to exist:

However,

that's a paltry amount of tags in the context of Ignition.

You will also probably need to have at least 1 tag created and polling at less than ~10 seconds, because most Modbus devices will close inactive TCP connections from clients after around this amount of time has elapsed. Otherwise you'll find your device toggling between connected/disconnected states.

2 Likes