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What are IO ports for?
hodeyp
Posts: 104
in AMX Hardware
I can understand the uses of serial, IR & relays but are IO ports used that regularly in automation projects?
What sort of control will it provide?
What sort of control will it provide?
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see the sample below
DEFINE_DEVICE //ni-3000
RELAY = 5001:8:0
INPUT = 5001:17:0
DEFINE_PROGRAM
PUSH[INPUT,1] TO [RELAY,1]
Good luck
You can use them to read the output of a VSS2 Video Sync Sensor to tell if a TV is on or not.
Some audio devices have 0-5VDC outputs on them which can be set to go high on certain circumstances like clipping or mute feedback.
You could also make a ladder circuit to do a basic analog to digital conversion.
IF(![dvIO,1]) // IF THE CABLE BOX IS OFF & AND WE WANT IT ON . . .
{
SEND_COMMAND dvCABLE,"'SP',9" // SEND POWER TOGGLE COMMAND
}
or . . .
IF([dvIO,1]) // IF THE CABLE BOX IS ON & WE WANT IT OFF . . .
{
SEND_COMMAND dvCABLE,"'SP',9" // SEND POWER TOGGLE COMMAND
}
That said, I mostly use them for monitoring the on/off state of components, either with a VSS or a devices output relay, or a current sensor of some type.
what is a dry closure btw?
AKA contact closure - a good old-fashioned switch or pushbutton, or contacts on a relay...
- Chip
Dry = no voltage present
Closure = switch
Hi Another good use is PIR motion sensors for rooms you have lots of equipment in.. i.e. an example would be people forgetting to turn equipment off in the rack when leaving work, therefore projectors are left running etc.. you could use the input from the motion sensor to check if the room is in use, if not then a wait that you have running in your code would be cancelled and if you AND this with the internal clock time you could check if it is late in the evening.. if all TRUE it shuts the equipment down (standby etc) for you so that it not powered all the way through the night wasting your lamp hours.
NB use Button_Event[DvTp,0] for running your timer under then any push from the dvTp will start your timer running again, also take lunch time or breaks into your calculations when picking your time for you wait!!
Be carefully when monitoring many motion detectors (say 10 or more) in a large system where the motion detectors cycle frequently. I had an experience last year where the Event stack became full from excessive push/release events generated by motion detectors. Once the Event stack fills, the NetLinx Master will shut down due to insufficient memory.
The solution at the time was to off load the motion dectectors and associated code to a second NetLinx Master. I was able to monitor at least 40+ motion detectors without a problem.
Try to specify motion detectors that don't reset so quickly.
In our lecture theatres we wire 2 PIRs in series since they have normally-closed contacts. They are all wired into a single I/O port. If motion is detected by ANY of the sensors it only causes a single event. If a second sensor is activated prior to the first one closing, the circuit is still open so no secondary event is creted. Not useful if you want to log people's actual movements in the room ("Which door did they use?"), but it is fine for our purposes. ("Any one there?") I've set up our theatres to shutdown after 90 minute of no PIR motion or TP pushes.
It seems to work well, though the media class get upset when watching a 2 hour film. To avoid this and maintain common code across our theatres, I've put in a flag (in our hidden admin pages) to enable/disable the PIR shutdown. The PIR is still used to bring on the house lights when someone enters the room AND the system is in the standby state. This has reduced the number of bruised-shins-in-the-dark from people leaving furniture near the door. In addition, if the system is in standby and there is no PIR motion for 5 minutes, the lights are then turn off automatically. A countdown on the TP indicates the time before light-off.
Another use for I/O ports that I'm considering is logging when the service panels on our desks are opened. That way I know when others (techs from various departments) are looking in the desk. Sometimes things get changed without people letting me know. Now the daily logs (emailed to me) will give me an early warning for my 7am shift.
Roger McLean.
If I wanted to use the pir sensor, how do I wire it up? I am using an NI3000.
Hi HodeyP,
Wiring is usually pretty simple, there are quite a few Motion sensors on the market (see google) that require, different supply voltages, the ones i've used on installs are 12V DC supply units therefore it usually comes with it own DC powersupply.
As far as picking up the switching i.e. motion in the room. There is usually a single wire that provides TTL type switching, ie. goes high to 5v when movement detected. This is what you will wire to into you IO port. You need to know whether you are looking for open circuit or short circuit switching though, AMX allow us to configure each input depending on what we are looking for. NI-X000 manual Pg123.
I've written and attached some code that shows this working for you .all you will need is a wire or paperclip to short the pins on the back of the NI-X000 processor to simulate a switching input.
i Hope this helps.
I am presuming there is some level of current coming from the IO port itself to create a circuit when connected directly to ground. is this enough to power a switch or PIR?
sorry for all the newbie questions, i am fully setup on my home cinema now and am exporing what else i can get my amx system to do!!
Yes, is there a way ??
Very few devices I have seen will operate on 5 VDC, most are 12. I pretty much always use an outboard 12VDC relay, and just short the IO to ground with the relay contacts, unless, of course, I am using a PCS or VSS, or other AMX box explicitly designed to work with the IO port.
The status pin puts out 12v. I came across AMX tech note 777 which says that for sensing the on/off state of a 5 to 12v input, a 2k resistor should be tied across the I/O port pin and ground.
Looking to see if anyone has actually had experience implementing this...
Thanks,
- Chip
Wow! This takes me back to when a control system was a large custom chassis loaded with relays and hardwired to the boardroom lectern control panel. The youngsters just getting started with control systems don't know how good they have it.
The relays I use have the diodes integrated. My preference is the Altronix RB-610, which is actually a circuit board with 6 12V trigger, 10A @ 120VA SPST relays to a board; the board is scored so you can break off a single relay, or however many you need. The board has the aforementioned diode, a jumper to convert it to 24V trigger, and a very convenient screw terminal for the connections.
The diode really is a must; there are lots of devices that aren't well isolated on their 12V trigger outputs, and the induction caused by the relay closing can totally scramble them. The Niles LS-1 light sensor is a good example - put a relay with no diode on the output of that, and it goes into oscillations when it trips.
I would like to use the 12v output to trigger my Rotel Amp's power switching. The amp has a 12v input (which is actually anything from 3v to 30v). What would be the best way to accomplish this? I'm used to using a relay port, which the 700 doesn't have.