Since I haven't gone that far off a KP with weigand, and assuming it's similar to a KAM, I believe the maximum distance they list for the reader to a KAM is ~10' and the still recommend STP for any readers, not a category cable, so I'd wager that cable construction has something to do with it.
Trouble with Essex Keypad and Elk M1
- Thread starter Ricksquan
- Start date
tmbrown97
Senior Member
That's crazy that it would only work when disarmed, not armed. You must be so close to tolerances. I don't think I would've ever guessed that had it presented in this way; that said, I always start by testing things close @ the keypad, then if all goes as planned, I'd pull the wire and mount it at its permanent home; I can only hope I would've put it all together that way.
Should I have been using shielded cable? I am using plain ol' cat5e. I admit I'm a bit clueless on how sensitive the wiegand signals are. I had seen warnings to keep it under 10' but I also searched cocoontech and saw that others have had success going much farther as long as the power voltage was sufficient so this issue was not on my radar.
I haven't had time to do the actually keypad install so I was able to try a few test scenarios out of curiosity. What I'm seeing this morning is that the problem seems more relevant to using wires on the same twisted pair. All along, I had been using green/white and white/green which was what was working to arm but not disarm. What I tried this morning is that using just one wire on different pairs does work. Using the green pair together or the brown pair together seems to lead to unpredictable results. Various combinations of using one wire on the brown pair and another wire on the green pair seems to work. This would seem to negate the idea that the problem was signal attenuation due to wire length. Rather something to do with the data0 and data1 signals interfering with one another? For those of you with more advanced electronics knowledge than me (most of you), does this make any sense?
Signals on twisted pair cabling only benefit if they are balanced signals. Wiegand data is not a balanced signal so the twisted pair would have no effect IMHO. Maybe there is interference that is causing the issue or maybe the input on the elk keypad is just more sensitive to noise than the typical wiegand interface.
You could try running the data on the white/color of two separate color pairs and and use the corresponding and use the other conductor from each pair both as the gound...
You could try running the data on the white/color of two separate color pairs and and use the corresponding and use the other conductor from each pair both as the gound...
I can't comment on the comparison of the M1 to a regular ACS, just not a valid item, but we use 100's of feet 22 AWG for readers, with the only factor I've really seen is voltage drop @ the reader causing issues. I can only comment on the distance that Elk stated on the KAM, which for almost all intents and purposes is a KP.
I'd toss a meter on the circuit and see what changes. Most likely a 5V on the clock/data pair and the 12V for the power. Possibly that large of an imbalance is causing something odd to happen, in conjunction with the distance factor.
I'd toss a meter on the circuit and see what changes. Most likely a 5V on the clock/data pair and the 12V for the power. Possibly that large of an imbalance is causing something odd to happen, in conjunction with the distance factor.
