Strange behaviour of PAC while using COM

Encountered a strange problem with PAC.
We've connected a device to PAC's serial port and made a test program that sends commands via COM1 every 11 seconds in cycle (7 diffirent commands, one at a time). After some time (several seconds or hours) it stops transmitting commands to COM port(we receive only part of last command, then silence), but programm still works (UserLED flash as programmed). After some time it continue to work normally and then transmission stops again.

Here is our test programm code:

Code:

{Initialisation}
OpenSerial(1, 1, 9600, 8, scOneStopBit, scNoFlowControl, scNoParity);
insource:=0;
SetLEDState(false);

{Module}
SetLEDState(true);
format(s, 'Y 3 0 ',insource:1,' ',#13);
WriteSerial(1,s);
delay("00:00:01");
SetLEDState(false);
delay("00:00:10");
case insource of
0:insource:=2;
2,3,4,5,6:insource:=insource+1;
7:insource:=0;
end;

Here is what we receive:

Code:

Y 3 0 0
Y 3 0 2
Y 3 0 3

.....

Y 3  

It can stop at any number.

We use 24V AC power supply for PAC COM. Serial cable used RxD, TxD and GND.
Tryed with two PAC units, results are the same, but second unit ceased transmitting after a few seconds untill reset.

 

Results of our experiments

IMHO there reason of this problem is overheating of some parts of the PAC unit when using 24V AC power supply.
We tryed to power it using DTR and RTS lines, as written in the Intallation Intructions, and also tryed a 12V AC supply. In both cases it worked fine for over 24 hours.
Though in case of 24V supply it would not work more then a couple of seconds.
We need to install PAC in several days and want to be sure it will work without any problems on this side.
Can you tell us what min/max voltage supply should we use?

 

Valery...

I use a HAGER DIN mount 24 volt power supply to power the PAC at home and it's run for about 4 months now without missing a beat.
Just bought a new one for a job so will dig up a part number and post tomorrow...

Mark

PS: would have used a Clipsal one but the Hager unit had literally been bouncing around in the toolbox for a few years!

>>>>>>>>>
Power supply Catalogue number is ST312.
240V to 12 / 24 Volt so you can run PAC and CNI off the one unit.

 

Valery,

Is there any chance you could be getting a runtime error via insource having a value of "1" and this not being covered in the case selector list ???

On the power supply side of things I have always used a good quality 18v AC plug pack 1A, (typically used to power domestic alarm systems). The better quality ones have a bit of filtering. As long as you supply a rail suitable to be rectified and split into a + & - 5-8 volts DC the RS 232 signals will function reliably from my experience.

 

The problem is definitely not in code. When we connect it to PC it works just perfectly, using the DTR and DTS lines as power supply. But when we connect an external power supply (tryed 12V, 16V, 18V, 22V, 24V) no reaction.

We have 2 devices we want to control using PAC serial port. It's NEC Projector VT590 and Kramer Switcher VP-724xl. We tryed to connect them on serials of 4 PAC modules. You mey not believe me, but only on one serial of one of 4 modules NEC worked. And works stable now, hopefuly. Kramer worked fine at home, but not anymore.
At the same time if we connect PAC's serial port to computer and read from it with HyperTerminal we get all the commads we need just fine. If we connect Kramer Switcher or NEC to computer via serial port and run the logic on PICED it works.
So problem is either in PAC serial ports, or in power supply.