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PTZ troubles with RS485 [SOLVED]

Posted: Wed Jun 11, 2008 2:19 pm
by robsmiler
Having also a PTZ cam here with an RS485 control interface using Pelco-D protocol. It ist this cam: http://www.security-center.de/de/scweb/ ... ?ARID=1332
Testing was a mess. Nothing worked in the beginning. But now it does!

Following settings are are valid for using cams PTZ:

Code: Select all

Switch 1..4 is address (I using Addr. 1 - On/Off/Off/Off)
Switch 5,6 Baudrate (set to 2400 = On/On - cam uses 8 Bit No Stopbit 1 Parity)
Switch 7 Protocol ( Pelco = Off )
In Zoneminder 'Control Type' must be set to 'PELCO-D'
'Control Device' /dev/ttyS0 or /dev/ttyS1 or /dev/ttyS2 (serial 0, 1 or 2 whatever you are using - this was why it did not work here)

'Control Address' 1 (for cam switches 1..4 set like mentioned above)
'Auto Stop' to 1.00 this stops movement after a short interval (not 1 sec if one would probably assume - did not measure but seems shorter)

No Track Motion
Control Capabilities
1. PELCO-D Local Yes No No No No H16

A word to RS-485:
Non of our HW distributors are selling RS-485 PCI interface cards anymore here in Germany. So I bought two different RS232->RS485 converters. Both do work. This one is not very practical http://www.buerklin.com/images/KapM/M104614.jpg because it needs additionally a serial 25 to 9 pin converter cable and costs at all about 30 Euro. The other one is a very small no name thing http://i13.ebayimg.com/07/i/000/b3/be/f528_1.JPG. This is sufficient, too. Cost is below 10 Euro.

Because things did not work in the beginning, I tried to measure signals at RS-485 with a standard oszilloscope. This is quite problematic. There are nearly no possibilities without a storage scope to detect the spikes on the line.

rob*