2014-02-22 15:52 GMT+01:00 Peter C. Wallace p...@mesanet.com:
for sinking inputs (like 7I70,7I76,7i77,7I84 field inputs) The best is NC
PNP
type. These will fail open (= limit) with short to ground or open wire
faults
Peter Wallace
Mesa Electronics
Dammit, I've already ordered NPN NC,
] Preferred sensors for Mesa cards, NPN or PNP?
2014-02-22 15:52 GMT+01:00 Peter C. Wallace p...@mesanet.com:
for sinking inputs (like 7I70,7I76,7i77,7I84 field inputs) The best is NC
PNP
type. These will fail open (= limit) with short to ground or open wire
faults
Peter Wallace
Mesa
2014-02-23 21:49 GMT+01:00 Peter C. Wallace p...@mesanet.com:
You can use NPN Proximity switches with the 7I77 but it requires external
pullup resistors (say 2K 1W)
I know, but the sensors are too cheap to make a special design for the
cards that are fine with PNP's. I rather take the cost
I am going to shopaholic a bunch of proximity sensors to replace mechanical
homing and limit switches for two machines with Mesa cards (5i25/7i77) and
then it struck me, what is the best option? NPN or PNP?
How do they behave if there's no power to them or if they fail? For example
a PNP NO, is it
On 22 Feb 2014, at 10:12, Sven Wesley svenne.d...@gmail.com wrote:
then it struck me, what is the best option? NPN or PNP?
I can't remember which type is preferred, but you probably want the shielded
type as they still work flush-mounted in metal.
You want to use NPN NC switches. This means that the circuit is
energized when in normal condition. If the switch is made the circuit
will open or if the power fails or if the wire breaks, the circuit will
be open and hence you will detect the condition on the input.
Oh and make sure it is the
2014-02-22 10:27 GMT+01:00 Marius Liebenberg mar...@mastercut.co.za:
You want to use NPN NC switches. This means that the circuit is
energized when in normal condition. If the switch is made the circuit
will open or if the power fails or if the wire breaks, the circuit will
be open and hence
] Preferred sensors for Mesa cards, NPN or PNP?
I am going to shopaholic a bunch of proximity sensors to replace mechanical
homing and limit switches for two machines with Mesa cards (5i25/7i77) and
then it struck me, what is the best option? NPN or PNP?
How do they behave if there's no power
I usually use 24 VDC PNP NO proxs for general use for a number of reasons.
If you have voltage at the output of the sensor, then the prox is
sensing metal. Most logic is positive which seems to help the debugging
and troubleshooting process.
However if the input card requires a sinking sensor
Yes of coarse it depends on the type of input circuit that you use.
Peter is correct for sinking inputs the PNP is best and for sourcing
inputs you will use NPN
On 2014-02-22 11:27, Marius Liebenberg wrote:
You want to use NPN NC switches. This means that the circuit is
energized when in
10 matches
Mail list logo