RS232 - I need more outputs

davidv

I need more RS232 outputs. I have 12 outputs that I need and the NI4100 I believe only has 7. What are my options? Do I really need to buy another master to get the outputs I need ?

the8thst

Put 3 of these into the cardslots on the 4100:
http://www.amx.com/products/NXC-COM2.asp

That will net you 13 RS232 outputs.

vining

You can also use an 8 pot serial server from Moxa for around $600.00 or buy individual serial servers like the SitePlayer for about $80.00 each. The nice advantage of the individual serial server is you go go up to 100meters and put the server with the device and just put a CAT 5 on the network to access the device .

John Nagy

Another potential choice, use an old AXCENT3 as a slave on AXLINK and get 6 more serial, 8 more IR, relays, and IO ports. Most older dealers have these sitting around. I've never seen one fail, either. I'm using 3 on my system now, one in each AVR location managing local sources. The NetLinx is at the main rack.

The AXCENT3 PRO has slots like the Netlinx, and you can add still more cards... of the older variety.

TurnipTruck

Be careful with Axcent 3 serial ports. They have a much smaller hardware buffer than native Netlinx serial ports. If you have a chatty device connected to an Axcess serial port, it's very likely that you may drop some bytes. The card slot serial ports have even smaller buffers.

There is a list of buffer sizes floating around. Regardless of what it says, I would not use Axcess serial ports if you expect strings longer than 50 bytes in one shot.

annuello

TurnipTruck wrote: »

Be careful with Axcent 3 serial ports. They have a much smaller hardware buffer than native Netlinx serial ports. If you have a chatty device connected to an Axcess serial port, it's very likely that you may drop some bytes. The card slot serial ports have even smaller buffers.

There is a list of buffer sizes floating around. Regardless of what it says, I would not use Axcess serial ports if you expect strings longer than 50 bytes in one shot.

When and Axcent3 is in slave mode I think all the traffic is shunted over AXlink (@ 20,800 baud) to the NetLinx master for the NetLinx to process. This is a bit of a bottleneck for the data, since each string coming into each port of the Axcent3 (presumably) needs to be wrapped to fit within an AXlink packet. If the incoming string is long it would probably be chopped into multiple AXlink packets.

Having said that, if your extra RS232 devices have a simple protocol this is a good solution, and I do exactly this on one of my "non-standard" lecture theatres. I agree that the Axcent3 is reliable & robust - power supply failures are the only issue I've seen.

Roger McLean
Swinburne University