I think it's just a pulse. The web page describes wiring it directly with momentary (i.e., doorbell) switches using phone cable which simply plugs in to the RJ11 jack on the Redy Temp. My understanding (somewhat limited) was that a doorbell button closes the contacts momentarily, triggering the pump to run one cycle, one cycle being long enough to bring the temperature up to the point at which the aqua-stat signals "off." My thinking was that, once the momentary switch signaled "on," the Redy Temp ignores any further "on" signals, until it receives an "on" signal AND the temperature at the aqua-stat is below the setting I chose. After describing this set-up on the Redy Temp page, they add, "this can also be accomplished with wireless motion sensors." I'm using MS16A motion sensors, a UM506 universal module and an RR501 two way transceiver.
The thing I didn't think of is that, with door bell buttons, I control how many times it gets pushed, but with the motion sensors, it's like me standing there pushing a doorbell button all day long, every few seconds, when people are moving around the kitchen and bathrooms. The Redy Temp doesn't have any problem ignoring this (at least, I don't think it does), and it seems to work, in the sense that the pump does, in fact, cycle on during "dormant" periods when motion is detected, but I don't think the x10 stuff will last very long if it is being switched constantly, and there is the issue of the constant clacking noise.
I guess I'm still confused about the delay setting, too. How does the delay "off" work when the universal module is set to "momentary"? Or is it irrelevant in that case? I guess my brain isn't wrapping around this very well, but I'm having trouble figuring out the point of this stuff if it isn't possible to do what I'm describing without the drawbacks I described. I mean, say I was just going to turn on a light as I walk into a room. I have two options, I can set to momentary, but then I have to listen to the transceiver and the universal module clack every few seconds (unless I remain absolutely motionless), or I can set to continuous, but I will find myself in the dark after 256 minutes, at which point I have to wave my arms. How are either of those more convienient than using a lightswitch located next to the door? The only application I can think of is a security light that comes on and then turns itself off after a few minutes, or a nightlight that does the same, but both of those are readily available at any home center for less money in a single package.
I think I must be missing some fundamental aspect here. Seriously, no sarcasm. Sincerely puzzled.