RS232 Port Sharing?
Tworhythms
Posts: 51
We are working on an existing system that has two Axcent 3 systems in two boardrooms and a new NI2100 in another conference room. We are controlling an older Lutron Homeworks system which has 2 RS232 ports. Here is the problem....there are no wires between these systems, there are only wires home-run to the lighting panel so I can't use one system to repeat strings or even use master to master since we only have the one NI. Another issue is that two of these systems are over the "50 Foot" recommended RS232 run length. We have tried to use a RS232 port combiner from B&B Electronics but it seems as though the long wire runs are prohibiting this device from operating properly (although individually connected, I can control Lutron). I tried locating it locally with one of the systems and it works fine. Here is the question....has anybody shared a RS232 port between multiple systems? I am going to try using a couple of diodes on the TX and RX lines between two systems the next time I am on job site to see if I can create my own port combiner.
0
Comments
What kind of wires to you have available at the HomeWorks processor from the AMX gear? Just Lutron KP wires or CAT-5s. If you have CAT-5s I would consider IP to RS-232 adapters if putting everything on a network is possible. You would prbably have send string from the Axcent 3s to IP ports on the NI which in turn could relay to HomeWorks.
I have a Cat5 for the NI and a Cat5 for one of the Axcent3 systems and the other one is a shielded 4 conductor wire (same as axlink). I originally thought about going with IP to RS232 converters but was worried it may break their budget. I've had good luck with the Perle IP RS232 adapters but they are fairly pricey. Do you have any recommendations for budget friendly converters. The Perle IP adapters use telnet sessions for communication. I was also thinking about using RS232-->485/422 converters and then using the port combiner that I have but as I mentioned I don't have an unlimited budget and need a failry reliable solution. I think the RS232 to IP converter might be a feasable option as there are active network connections at these systems. I have only used these converters for outgoing communications from a NI. Would I just create a ip_server_open connection on xx port and then relay everything on that device/port out to Lutron? Thanks for all the input!! Great ideas.
and is relatively inexpensive at about $80/port. It has the ability to function either as a server or as a client, but I'm not sure that it is important in your situation which it functions as.
If a client session is started to one of these devices (with the device configured as a server), anything that goes into the RS232 port triggers a string event in the data_event for the IP port that the client is using.
Actually, with two of these devices, you can do RS232 over ethernet -- set up one as client and the other as server, and when they connect, anything that appears as input on one of the devices is automatically sent as output on the other.