NetLinx Relay to Control a Line Conditioner

Pure_Audio

I have a system comprising of NI-2000, and MVP-7500, intended for controlling Audio/Video equiptment. The components are centrally powered via a PS Audio line conditioner.(PD 3.5). This power conditioner has a 12v DC trigger, which has a female RCA input. I am thinking of using a relay port on the NI-2000 to fire the 12v trigger for powering the equipment on/off. I have decided to get a 12v adapter with a male rca on one end, and the typical two-prong plug on the other end. I will then cut off the plug end and expose the bare wires, wich I will attach to the NI-2000. After doing this, would I need to do anything else, in order to get the NI controller to fire a 12v DC to the line conditioner? Any suggestions will be greately appreciated.

Darkside

Couple of things...

I'm not familiar with this particular conditioner, however, you must be very sure whether the line conditioner is looking for volts or a dry contact closure. In other words, does it want you to supply 12v across the female RCA or does it simply want a dry contact closure.

I can certainly read your post both ways....

If it wants volts, your 'plug pack' wired correctly across the input via an NI relay will work. Check the conditioner input tech detail to make sure your plug pack will suffice. I would also recommend a regulated supply.

If it wants a contact closure only - in other words it has a control voltage already on the female RCA port - then wiring an NI relay across the female RCA will be fine

wrote:

After doing this, would I need to do anything else, in order to get the NI controller to fire a 12v DC to the line conditioner?

Just code the relay to fire in your source code as you normally would - perhaps with your 'source select' or 'system startup/shutdown' routines.

Daniel Tehan

You can also pull 12V off of the IO ports on your NI-2000. When the I/O ports are not being used for sensing (VSS or PCS) they can also be used for control output. Each of the numbered outputs is a switch to ground that is rated for 200mA @12 VDC, which is also the rated output of the PWR pin. The I/Os are not a true dry closure as the Relays are, but if the voltage swing is enough to trip your power conditioner it will work.

Just wire the +12V PWR pin to the RCA (I assume the center conductor, but you should check that) and one of the numbered output ports to the sleeve of the RCA. Then you can control the I/O port as you would a relay with ON and OFF in your program.

I have not tried sensing off of the same set of I/Os as controlling with voltage. From looking at the documentation I would think that it would work.

Pure_Audio

I talked to the Tech Support at PS Audio this morning. It turns out that the input trigger on the line conditioner expects 12volts. So, if NI-2000 will send out 12vDC, this may be a straight forward solution. I still will appreciate input/suggestions from members with more knowledge/experience. Thanks

ericmedley

Pure_Audio wrote:

I talked to the Tech Support at PS Audio this morning. It turns out that the input trigger on the line conditioner expects 12volts. So, if NI-2000 will send out 12vDC, this may be a straight forward solution. I still will appreciate input/suggestions from members with more knowledge/experience. Thanks

One thing I've found over time. while it may seem easy to grab power off the AMX power supply (via the +12VDC next to the I/O) I'm finding that more and more, I want to isolate the power supply used to power the AMX system from the other devices. As our systems get larger and larger and begin to control the many other systems in an installation, power isolation can become critical.

I'm to the point that I'll almost always isolate any 12 volt triggers that do not directly control things in the same rack. I even use a secondary power supply to control things like projector screens and whatnot. Thermostats are most definitely isolated.

If it were me, I'd get a 12 volt relay and use the AMX's 12VDC to operate the relay and then use the relay to switch a second 12 volt power supply (wall wart) to run the power conditioner.

I can't count how many times some other peice of gear has burned up my stuff because it wasn't isolated.

Just a thought...

Pure_Audio

The suggestion about isolation is well noted. In fact, in this environment, the A/V equipment connected to the line conditioner are actually on a separate circuit (i.e. the conditioner is connected to this circuit--two 20amps , and from there, all A/V components are run off of the conditioner. The projector uses one of the 20amps.). The AMX control system is going to be connected to an Isolation transformer, which will be running off a separate circuit--the main house circuit. I think, this might be sufficient protection?

Darkside

I agree with not relying too much on the NI PS for a 12volt rail for lots of peripherals.

In this case, I would feed an external 12VDC to the NI relay and switch it to the PS. Then if something goes a bit pair-shaped with the PS, the NI most likely won't be affected.