Hi All, I have 2 UM96 modules that generally work OK but. . . . .
Both have TTL-RS232 (MAX232) converter chips added to them as they seem not be true RS232 levels and some laptops dont like working with them.
We have these devices 50m apart in open air (direct line of sight) with one unit mounted at 1.5m high and the other at 2.5m high.
A commercial data logger is connected to one end (have tried a computer there too to rule out the logger), and a computer is connected to the other. A serial terminal is used to send simple commands to the data logger and then the data logger streams lines data back. The ammount of data depends on how long it has been logging, but generally is only several hundred bytes maximum.
The Problem(s)…
#1. When the data is being sent back from the logger the radio link occasionally drops anywhere from 1 to 10+ characters. This essentially screws up 1 or 2 lines of the data coming from the logger.
#2. We are normally able to send a CTRL-Break to the logger which will cause it to stop sending data. Using the UM96 radio link the CTRL-Break rarely gets through, and usually just stuffs up the data coming from the logger.
#3. When sending commands to the logger (which echos the characters typed back to the sender) sometimes it drops chars here too. Sometimes they are received by the logger and not echoed back and sometimes the logger doesn’t ever get the char.
I have used other radio links with no problems such as Aerocomm, Maxstream, Maxon, RFI, and others. I guess it really is a $40 radio, or can someone prove me wrong. I would love it if someone could.
Best Regards