CCTV24HRS 0 Posted April 2, 2008 Hello, Is anyone able to provide me with a pin out diagram of which 2 pins to use for RS485 on a Speco DVR 8TN. There are 2 Alarm I/O and RS485 ports on the rear of the unit. There is also a separate RS 232 jack. After reviewing their manual, it says pin 1 is RS485 D+ and pin 2 is RS485 D-. There are 2 rows of 9 pins. I can't get a grip on which pins are number 1 or 2. I would like to hook up a Speco CVC927 PTZ camera to the DVR and use the RS485 to control the functions of the camera. I believe this is possible through the DVR without the use of a separate keyboard such as the Speco KBD927. I have emailed Speco and have not heard back from them. I work 12 hrs a day and just don't have time to call them so I thought I would get some advice from this forum. I've been installing DVR's and cameras for several years just a s hobby for friends and family. I have never ventured out into the PTZ area and RS485 communication. Share this post Link to post Share on other sites
mr.surveillance 0 Posted April 2, 2008 If my interpretation is correct from page 125 of the manual pin one is bottom left facing the rear of the unit. (see illustration in manual) Good luck... Share this post Link to post Share on other sites
