LabVIEW
Handling same set of IO from two PCs
Refer the image below :
As can been I have two test rigs that are powered by a single hydraulic power source with 3 Pumps. Right now, Phase 1 is fully functional and the customer wants to add another Test rig as Phase 2, but to keep cost low, he wants to use the existing power source.. Complications start to arise :
1. The oil tank has sensors for level / temperature / cleanliness etc. Out of this, level is digital input and rest both are analogue signals.
2. The 3 pump motors have Overload relays to signal health.
3. Any of the motors can be used and so if Motor #1 is chosen by PC #1 then it should be not available for PC#2. ( Mutually exclusive )
Maybe reading sensors can be done parallelly also, but controlling relays in mutually exclusive manner ? Two options exist :
A: By Hardware OR'ed diodes connected to relay coil from both DOs
B. By a shared variable between PC#1 and PC#2
Just to outline the issue I have cited above as example but in reality I need to handle something like 30 DIs / 14 DOs / 12 AI s - which are common to both systems ! I am trying to find an optimum method to do this. have so far not handled Network Shared Variables and so do not know what limitation they pose - my code while loop time is about 25 millisecond. In any case PC#2 should be aware which pump is chosen by PC#1 and vice versa.
Any views on above or alternate methods ?
