Rig start up sequence

[ARXW]

Hello,

I'm looking for a way to create a laboratory start-up sequence.I'm using Labview 6i, and using the fieldpoint FP-CTR-502 counter input module. For the purpose of start up we are going to use the 4 discreet output channels on the CTR-502.

I'd like to know how the to issue the bits I want in a sequence so as to enable various stop buttons, valves and motors on the rig.

The bit logic should look like this...:

Discreet Channel No:
3 2 1 0
-------
Step 1: 1 1 1 1 Start/Reset (watchdog state?)
(Stop button shut, control valves shut, heaters shut, DC motor shut)

Step 2: 1 1 1 0 Enable stop mechanism (powerup)
Step 3: 1 1 0 0 " " "
-------------------
At th
is point the program should stop and should only be able to continue once the enabled stop button has been manually reset (a FP-AI-110 signal will feedback the signal to the program that the emergency stop mechanism has been reset, thus enabling the sequence to continue).

Step 4: 1 1 0 1 Enable control valves.
Step 5: 1 1 0 0 " " "

Step 6: 1 0 0 0 Enable the three heaters
-----------------
Channel 2 bit is the 'master' bit. The heaters controlled by channels 0 and 1 cannot be ON until a 0 is issued to channel 2.
Program should stop here for adjustment of set point. No feedback required just a click on a 'continue' button, once the required temperature is set.

Step 7: 1 0 1 1 Heaters not required are shut(channels 0 and 1)

Step 8: 0 0 0 0 DC motor enabled

And that's the whole program! I would have thought that a sequence loop would be appropriate.

Cheers,

[vg]

Hello,

According to your email, I beleive that the best LV technique to use is the State Machine Architecture.
Using a Sequence should work also, but it is not very flexible. The State Machine is a lot more flexible.

Check the State Machine documents and examples programs at the NI website: www.ni.com

Try the NI Developer Zone:

http://zone.ni.com/zone/jsp/zone.jsp

Use the search engine. Just type "state machine"
and it will give you some documents that might be useful for you.

I hope this helps.

vg.

[Aaron_G]

One thing to consider is how you want to address the output channels on the FP-CTR-50X modules. You can individually address each channel by the channel name/number, or you could create a multi-channel item allowing you to address all 4 channels at the same time. If you address all 4 channels simultaneously, there is a little trick to make it work correctly. The 4 output channels are channels 12-15 on the module. Each channel would be represented by a single bit in a 16 digit number with channel 15 (Output Channel 3) being the most significant bit. Thus for step 1, you would write a value of 0xF000 or decimal 61440. Step 4 would be 0xD000 or decimal 53248.

Regards,
Aaron