If a gauge, flow meter, uses 485 communication and works fine in the office but not on site, what could be the reasons?
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This post was last edited by conde on 2021-2-10 16:51. If a meter, flow meter, uses 485 communication, works fine in the office but not on site with no communication, what could be the reasons? It’s a turbine flowmeter. Communication works fine using the MODSCAN software, but when sending them to customers, half of the units fail to communicate. However, when those units that communicate properly are connected to the faulty lines, communication works again. What could be the reason? I just received feedback from the customers and I can’t think of any possible causes. An engineer will be sent over after the New Year
First, ensure that the laptop you carry with you is a device that functions properly for communication; use it to replace the customer’s computer in order to establish a connection. If communication is possible with this laptop, it indicates that the serial port on the customer’s computer may be damaged or faulty. It’s happened here too – it really gave those engineers a tough time
It’s very likely to be a wiring issue; for 485 communication, certain requirements exist regarding the wiring when the distance between the devices is large
The computer is working fine, but the gauge at the site was malfunctioning; after replacing it with another gauge, everything worked properly again
The computer is working fine, but the gauge at the site was malfunctioning; after replacing it with another gauge, everything worked properly again
It’s most likely a problem with the instrument. Try reducing the baud rate if the instrument is not working properly.
Waiting for the moment when the truth emerges. . . .
Consider the following points: 1. The communication distance is too long. 2. There is interference. 3. Connect in series, not in star configuration. 4. Add a reflection resistor.
It’s fixed now; one of the small resistors was changed. I’m not sure what it was, but it is said that this increased the driving power for the 485 interface
Terminal 120 ohm reflection resistance