Best guess? Whatever the acceptable timing is between digits for pulse telephone dialing. Really. That's where it comes from. Its also why pulse format is so slow compared it CID or other single tone/digit formats.
Hi Bob, Not even gonna hint you are wrong!! No way!!!! But, what I will say is that if Bager2700 hasn't already Googled Pulse Dialing AKA "Rotary Dial" the answer is as follows.
======================================================================== Within the Bell System the dial pulse period is nominally one-tenth of a second long, permitting a rate of 10 pulses per second. Modern telephones are now wired for push-button dialing (see below), but even they can usually generate pulse signals when the push-button pad is operated in conjunction with electronic timing circuits. ========================================================================
Hey guys it not, the pulse dialing (make/break ratio) specs that I am looking for but the 4/2 protocol ... so communicator goes on line and completes it dialing via DTMF or Pulse. Then waits for the Central station RX to come online with its format tones. How long will the 4/2 wait for this, how many milliseconds are the data bursts and timing of the data.
so ONLINE-<wait how long?> <CS, tones approx 750ms><communicator data bursts time?>< no pulse time?><next data> then finally <kissoff approx 750ms> <communications completed.>
The mystery is what the actual specification are for the 4/2 data format?
Please understand that we here are/were Alarm Dealer/Installers. We just have to properly connect the phone line thru a RJ-31X block, program the panel with the proper phone number for the Central Station Receiver, Enter the proper Account Number for the Customer in the proper fields and save it. Then trip a zone and check the Test History for the Receiver and all is good. I never cared about what you are asking. That being said, I did a little Google and found the following.
That may get you a little closer. Beyond that I am at a loss.
Thanks Les , finding info on the new formats SIA, FSK, IP, Contact ID, is so easy but when we are talking before internet, and fax machines, kinda the old voice dialer days with the circular recorder tape (that is a whole other subject) The 4/2 - 3/1 was a massive upgrade, we are going old school and the info, while just seems to be missing.
. I'd have to echo Les's reply. As installers we didn't have to know how it worked only if it did or didn't. As a matter of fact, it's the same with SIA and CID. These are thing we didn't have control of anyway, so it wasn't/isn't of any importance. If communication doesn't happen, it's a matter of a control panel defect, line problem or (unlikely) central station problem and the cure is process of elimination. ie, change the panel , etc. We don't have the means (tools) of measuring these functions readily available - - - - anyway. And now -- - - - - - 4/2 format is of little interest to most and actually unknown by the younger generation of installers.
Hello, I'm not really sure that there were standardized timings for pulse formats, I have many systems that have different delays in them.
I can tell you that the duration for the ACK/HANDSHAKE tone is slightly different between receivers, my Radionics D6500 defaults to a 1.2 second tone, my ITI CS4000 is about 2 seconds, and my Radionics D6000 is about 2.8 seconds. I haven't ever had a panel really have trouble with tones that are around 1 second, though I'd suggest going slightly longer than this, as the really old panels will need it to detect the tone reliably.
A good reference for the digit timing and such is the Radionics D6500 program entry guide, as it has defaults for how long the receiver waits for the next round of digits, and how long it looks for the next digit. The receiver defaults to waiting up to 6 seconds for the next round of digits from the panel, indicating that it won't take longer than this for panels to send the next round of digits. The receiver also waits up to 1.4 seconds for the next digit in a round by default. Effectively, the panel shouldn't have more than 1.4 seconds in between digits, and shouldn't take longer than 6 seconds to send the second round. Additionally, the panel should wait longer than 1.4 seconds before sending the next round of digits, so that the receiver doesn't count it as part of the first round. There doesn't seem to be an industry standard for a minimum for these values, so it is not easy to give suggestions on what you should use, but those maximums are good things to keep in mind. If you'd like, l could take some measurements of what the various systems reporting to my receivers are using, perhaps it could be useful to you to have recordings of multiple different panels reporting?
In terms of the time between the panel dialing and the receiver answering, it really depends on how long it takes for the call to be routed to the receiver, and for the receiver to detect and answer the ringing call. Most panels will wait about 30 seconds for this process, but some have an option to extend it to 45. I have never seen it actually take that long for the receiver to answer, but you also have to consider that most receivers will provide multiple different handshake tones for different formats, and sometimes the 1400hz or 2300hz one isn't early in the list. I'd say 30 seconds is a reasonable amount of time to wait before making another dialing attempt.
I'm not sure if you're trying to make a dialer or receiver, but if its the receiver, you should also remember to wait about 2 seconds after answering the line before sending the handshake tone, this lets the line stabilize and is a standard feature of most receivers. Another thing to consider if making a receiver, is to support the pulse formats other than 4+2. There are also 3+1, 3+1 with checksum, 3+1 extended, 3+1 extended with checksum, 4+1, 4+1 extended, 3+2, the list goes on and on.
Hopefully I can be some help to you, as I know that finding information on the really old formats is quite hard. I'm personally trying to find information on the Radionics BFSK format.
So Kieth - - - - That's really cool that you know all of this but the question is ; how is it that you know all this info? It's not something typically an installer would know. . As an aside. I think the OP won't benefit from your info. He's not a regular here and will likely not check back
I'm actually not in the industry yet, I just got a job at a local alarm company, so soon I will be, but I haven't actually done installations yet. I have been studying the older central station equipment and reporting formats for a little over a year now, as I am designing my own receiver, so I have figured out the normal timing for pulse formats after dealing with them for a while. Working with those three receivers I listed has helped a lot in understanding how the pulse formats work and learning the timing that they use as well.
I don't really expect the OP to respond, but thought I'd share what I know anyways in case they do.
Hey Keith Thanks for the info, it sounds like you enjoy actually knowing how things work instead of just, working or not working. I do not have info on Radionics BFSK but if I fined some I will let you know.
Regarding 4/2 at 20BPS I have reversed engineered the data stream and have found the following: The digit pulse are 32-40ms depending on the TX unit used The space between digit pulse are 12-17 ms and then repeat for the number of digits required for the account. Then, the spacing this is followed by 663-672ms of time between the first set of pulses to the next set. The spacing between rounds of data is 3.25-3.76 seconds.
if the account number was 0000-AA then the complete data transfer time is 75.12 seconds which is about as bad as it can get. If the account was 1111-11 then this can be reduced to 3.53seconds which is very slow to today's standards but that was how it use to be.
The ACK/Kissoff for approx 750ms is all that is required in most cases however older panels like a 750ms to 1500 ms depending on the format used. I guess this info will just pass-over most "installers" on here but not ALL.... here is to your Receiver Unit you are building looking forward to hearing more.
Interesting findings, though I think that your timing values for the pulse on/off time may be a bit off. At 20pps it is 25ms on, 25ms off (10pps is 50ms on, 50ms off), typical space between digits is about 300ms, and time between rounds is about 3 seconds. The longest possible transmission is FFFF-FF, an "F" is 15 pulses, which takes about 20 seconds for the whole double round transmission. Using 10pps with the same timings takes longer, but is nowhere near 75 seconds, maybe 40 at the most. This was taken from a Scantronic SC800 panel transmitting to a Radionics D6500 receiver, It is about the same for other panels and other receivers, but this seems to be the average based on tests I've done earlier. You may have been measuring the 40pps or otherwise knows as "Radionics Superfast" format, which has 12.5ms on/12.5ms off for the pulses.
I'll probably make some form of post here showing my receiver whenever I get around to finishing it. I have the design for the phone line interface done already, just need to figure out how I'll be detecting the pulses from the panel. It'll be supporting Contact ID, pulse formats, BFSK if I can decode it, my custom modem format, and maybe a few other DTMF formats.