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Thermal Overload
The threads that wouldn't die...
- PC reliability?
- Windows, real time
- PID loops
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- Replacing people
- MS 'monopoly'?
- Software quality
- Where do we go from here?
- Why pay?
- PC reliability?
- Windows, real time
- PID loops
- PCs vs. PLCs
- Replacing people
- MS 'monopoly'?
- Software quality
- Where do we go from here?
- Why pay?
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from the Automation List department...
RS 485 Modbus communication
How can device dependent operation (reading, writing) be performed on RS485 Modbus network, i.e. Modbus works in Register format?
What is the function code/sub-function code for device dependent operations (reading and writing)?
What is the function code/sub-function code for device dependent operations (reading and writing)?
The first byte in the Modbus protocol is the Device ID. If you set it to 0 then the message is a broadcast to all devices on the network. If you use a number other than 0 then only the device with that device ID responds to the packet, all other devices will ignore it.
Fred Loveless
Senior Application Engineer
Kepware Technologies
http://www.kepware.com
Fred Loveless
Senior Application Engineer
Kepware Technologies
http://www.kepware.com
What plc are you using??? Schneider?
From Control Engineering magazine...
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Above articles copyright 2008 Reed Business Information.
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