Sentinel 21" DVR Monitor Combo - Control Via RS232

[JohnHappy 0]

I own the 4 camera and 8 camera version of this Sentinel 21" DVR/Monitor 'combo' product. I tried to set up an RS232 (serial) connection between my PC and the devices and, using the brief RS232 documentation, control the devices. I've spent hours trying to get a response from the units. Don't know what I'm doing wrong. Has anyone out there discovered how to communicate with these Sentinel devices via RS232?

 

Sentinel SC21FD3044-161 (8-camera version)

Sentinel SY21CD5444UQ-A80 (4-camera version)

 

Lorex Technology purchased Sentinel years ago.

Lorextechnology.com

[Soundy 1]

RS-232 ports on a DVR are usually used to control devices like PTZ cameras... not for other devices to control the DVR. Are you sure these machines even support this type of usage?

 

Remote access/control of your DVRs from a PC would typically be done via network.

[JohnHappy 0]

The RS232 connection was designed to control the DVR on the devices in question.

 

I've posted the user's manual for my 4-camera DVR on my website ---

 

http://www.johnhappy.com/DVR/manual.pdf

 

The pertinent RS232-related pages are page 11 and page 29 according to the page numbers printed on the PDF file pages. Your version of the Adobe Reader might refer to the pages as page 15 and 33 should you use the page up and page down arrow buttons to navigate the file

[Soundy 1]

Hmm, that is somewhat vague. What sort of cable are you using to connect the two? If the DVR has a male port (same as on your PC), you may need a NULL MODEM cable. If it's a female port, a straight-through serial cable should work, or you can wire your own - connect pin 3 (TX) on your computer's serial port to pin 2 (RX) on the DVR, and wire pin 5 to pin 5. That SHOULD be all that's necessary.

 

At that point, you should be able to fire up HyperTerm or whatever other terminal software you want, to send the commands.

[JohnHappy 0]

Soundy .... vague is the appropriate word for it. I tried a null modem cable, a straight cable, building a custom cable. While testing each cable I tried every way to send the commands I could come up with and used HyperTerminal and a couple other RS232 command software programs. Would you do me a favor ... take another look at the list of commands page. Pick a command and let me know what string of command code you would send via HyperTerminal. BTW, I called Lorex Technology, the company who bought Sentinel. Their technical support team could not help me. My DVRs are considered discontinued and very few people try to set up RS232 control. The brevity of the documentation would lead one to believe it should be a no-brainer. The part of the documentation which states that I should be able to press "R" on my keyboard - press just one key, using readily available RS232 command software to stop my DVR is hard to understand.

[Soundy 1]

My first hunch, assuming all the communication parameters are correct, would be to simply type the control codes into HyperTerm (make sure it's showing you're connected).

 

If that doesn't work, you could try something like Comm Operator Pal (http://serialporttool.com/products.htm) to build a complete command set as shown in the DVR manual (FFC0??727F for "STOP" command, for example... the ?? I would assume is the ID number of the DVR, which would be set in the DVR menus).