Article - CS379578
Addressing a Bit within a Word in Modbus Drivers for PTC Kepware Products
Modified: 18-Sep-2024
Applies To
- Kepware Server (formerly KEPServerEX) 5.20.396.0 to 6.16
- ThingWorx Kepware Server (legacy) 8.0 to 6.16
- Modbus ASCII
- Modbus Ethernet
- Modbus Plus
- Modbus Serial
- Modbus Unsolicited Serial
Description
- How to address a Modbus bit in a word
- How to read just one bit with Modbus driver
- I am having trouble configuring kepware properly to allow me to read a modbus word as a 16 bit integer.
- I am trying to communicate from a schneider zelio PLC using modbus over to our FactoryTalk View 13 application.
- The word I need to use is 4020, I need to write the values from this word to a tag that can be split up into a bit integer. How I can achieve it ?
- We are working on a project that will have multiple Modbus TCP Channels defined.
- We have them configured but since we don't currently have access to the equipment we have set each Device as Simulated.
- We have several tags defined as Modbus registers as "short" which contain 16 individual bits (of course).
- But we also wanted to be able to address individual bits within these words.
- So we defined 16 tags that referred to the same register but using the bit notation for the tag address.
- We are receiving the information for the entire word just fine but the tags defined as bits within that same word are always 0.
- Is this not a supported configuration?
- Or is this behavior due to having the device set to Simulated?
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