Hi,
I'm trying to set up a tag change script but I am having issues reading and writing to my Modbus coils on Designer. I can read and write to the Modbus coils just fine through the OPC Quick Client, but when I create an OPC tag and connect it to the Modbus register, I get "Uncertain_InitialValue" under Quality. I have tags set up from other devices connected via TCP driver and those seem to be working just fine on Designer. Any ideas of what could be happening?
You mention both coils and registers. Not all devices can write to individual bits of holding registers (especially modern Schneider pieces of junk).
Share more?
I'm sorry, I didn't mean to say register. When I connect the OPC tag to the Modbus Coil I get the Uncertain_initial Value. I am using a Sealevel eIO 110 modbus device. They seem to work fine on OPC Quick Client but can't create an OPC tag that I can read or write to
And you are confirming that the device's data matches what you read or wrote?
Makes me suspect other problems. Please share the manually addressed OPC Item Paths you are trying in your OPC tags.
Yes I am just writing 1's and 0's to the tags. Let me share some screenshots
This is how I set up my OPC tag in Designer.
This is the screenshot of me reading the value of the modbus coil on ignition
This is my address setup for the device
Leave out the 1. when using mappings--they have the unit embedded in the symbol.
(Better is to not use the mapping facility at all.)
Do you mean leave out the 1 in the OPC item path?
And the dot. When you use mapping names, the unit number is included in the mapping, so it doesn't belong in the OPC Item Path.
But anyway, make a tag with the manual address [DD6]1.C1 in the OPC Item Path and see what you get.
(Based on your examples, you may also need to adjust the device's advanced setting for "Zero-based Addressing".)
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I still get the same "Uncertain_InitialValue" under Quality, and can't read/write to the tag. I have zero based addressing turned on and I know that is the correct setting.
Can you remove all of your address mappings and then edit/save the device? I think you may be running into a known bug with the address mapping page.
Alternatively, create a new device instance, do not add an address map to it, and only create the direct address OPC Tag ([device]1.C1 etc...).
That didn't seem to change anything
Maybe time to give support a call.
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Thanks for the help