I'm trying to determine whether a typical Discrete Input Card (VE4001S2T2B1) will be sufficient or whether I should purchase a Multi-Function Pulse (VE4015) to read in the pulses from a turbine flowmeter. The pulse widths are 0.260 seconds long and will have a period of 1.5 seconds at maximum flowing conditions (0.66Hz). The system is an M-Series DeltaV. Has anyone had experience with something like this?
Thanks,Mike
These are very slow pulse rates. The standard DI is rated for I beleive 75 HZ. You're application indicates about 4Hz max, so yes, the typical discrete DI will work. There is a bit of a difference between the DI channel and the PCI channel on the multi-function card. The DI has a pulse count register that counts and cannot be reset. You have to handle the register in the control module. The PCI input is designed to use with the PIN block and offers a reset on the counter, as well as a configured flow rate based on the calibration of the pulses.
But you can definitly get the pulse rate of 4Hz handled with the typical DI channel.
Andre Dicaire