Westec 5000 system OAT (Outside Access Terminal) Information?

[ecborgoyn]

As I approach the end of the initial phase of the Westec 5000 to Elk M1G upgrade, I'm looking to do something with the Westec OAT functionality. This external keypad is currently outside of our garage overhead door. It was used both for arm/disarm/status of the W5K system as well as control of the garage door opener.

One thought is to build a simple interface between the OAT and the M1G. Perhaps via the ethernet/XEP. Or perhaps via hardwired signals. I'd use something like an Arduino module for the interface.

Does anyone have any technical information on the OAT? It has an eight wire interface to an AM5241 module. This module 'translates' the OAT protocol into the Westec keypad bus. The AM5241 sits on the normal W5K keypad bus. Since the AM5241 module is so old and uses 7400 series TTL devices, and since it's only a two layer board, I've started to reverse engineer the interface a bit. So far I know that he AM5241 supplies +12VDC and +5VDC to the OAT. There also looks to be a four bit bidirectional bus of some sort between the AM5241 module and the OAT itself. I've also gleaned from the W5K documentation that the four bit bus also somehow controls the four leds on the OAT. So I'm getting there..... My next step is to power up the OAT/AM5241 and 'scope the bus signals to see if keypress info is transferred somehow...

Anyway, does anyone have or know of a source for engineering level specs on the OAT (or AM5241 interface)??

FWIW, I'm NOT trying to emulate M1G keypad functionality on the OAT. I'd be happy to have arm/disarm, GDO control, and perhaps a door bell function. The OAT has one button that is the GDO control if you entered a valid system access code but is a door bell if you didn't enter a valid access code. Kind of a nice feature.

I know that I can replace the OAT with a wiegand (sp?) interface keypad and use the Elk-M1KAM. But that expensive and much less fun.

Thanks.

 

[ecborgoyn]

I know it's a long-shot. But I was hoping to find some Westec 5K guru out in the community.

 

[JonW]

I have no knowledge of this keypad to add, but if you completely strike out on information, maybe you can just wire directly to the keypad circuit and build your own decoding matrix with an Arduino. You might even be able to add more logic/control options that way also.

 

[ecborgoyn]

JonW,
The OAT keypad is a quality, environmentally sealed assembly. The internal electronics (switches, decoding, etc) are in a fully potted 'brick'. I need to connect to the 8-line interface or destroy the device sealing. At that point I'd buy a new keypad...

Thanks.

 

[tmbrown97]

If this were me, I'd consider making this to work with the M1KAM by making it talk weigand... the KAM can provide voltage outputs for armed status and incorporate the door controller.

 

[Del91574]

I wouldn't suggest a KAM necessarily in this case. The only positive to using one, as mentioned, is the ability to spit weigand into it, however you can use something like a Corby 6522. Essex units would also work, but they're going to be more money.

Unless you brew your own, I can't see a product on the market that'll give you the same as what you already have, but you can come close.

 

[tmbrown97]

I wouldn't suggest a KAM necessarily in this case. The only positive to using one, as mentioned, is the ability to spit weigand into it, however you can use something like a Corby 6522. Essex units would also work, but they're going to be more money.

Unless you brew your own, I can't see a product on the market that'll give you the same as what you already have, but you can come close.

It sounded like he was trying to roll his own bridge - that's why I suggested the KAM, as it gives you an industry standard protocol as well as access to arm status.

 

[ecborgoyn]

It sounded like he was trying to roll his own bridge - that's why I suggested the KAM, as it gives you an industry standard protocol as well as access to arm status.

Indeed, I'm hoping to design and fabricate a bridge. I DO like the idea of using the KAM module as the interface to the system bus. My initial thought was to use a set of digital inputs and outputs (zone inputs, digital outputs). Using the KAM gives me more control and flexibility. When I started to investigate the OAT interface, I was hoping that it was talking weigand protocol with the interface module (perhaps it is.....). But now I see this four bit data bus and think otherwise. But YES, I like the design of a custom bridge between the OAT and the KAM, and using the weigand protocol... Thanks.

I posted this only to see if someone in the community might have specific information on the OAT bus interface. When I find the time to 'scope the interface bus I'll post my results....

I know it's a LONG shot finding technical details on a ~20 year old device.

 

[gatchel]

I wouldn't suggest a KAM necessarily in this case. The only positive to using one, as mentioned, is the ability to spit weigand into it, however you can use something like a Corby 6522. Essex units would also work, but they're going to be more money.

Unless you brew your own, I can't see a product on the market that'll give you the same as what you already have, but you can come close.

Don't forget the securtiron DK-26 too...

If the original unit has 8 wires to a separate interface is sounds like a matrix output of some sort where certain key presses reference ground or positive voltage. Just a guess though. Check out the manual on the DK-26 you'll see what i mean.

http://www.securitron.com/Other/Securitron/Documents/InstallationInstructions/DigitalEntrySystems/DK26_500-16900.pdf

Page 4

 

[ecborgoyn]

I do have a little more information on the 8 wire bus. I have a copy of the W5K installation manual. The attached image shows the names of the 8 lines. One is ground, one is +12V, one is +5V, four are a 5V TTL bi-directional bus (based on the circuitry on the interface board. The final line is a bus control line, perhaps input/output direction control..

You also see from the signal names, that the four digital lines also seem to control the four LED's on the OAT module. Maybe when no key is pressed, the interface module simply drives the 4 lines to control the LED's. When a key is pressed, this 5th signal is used to indicate that the 4 bit bus is 'turned around' and used to transmit the keypress data. The LED's might blink (and if I recall correctly, they DID blink with keypresses). I thought the blink was an intentional visual feedback of the press, it might just be an artifact of the bi-directional bus design.

As I'm typing this the bus design might be coming to me....

 

[emale]

I have already upgraded my 5000 to an m1 and also wanted to continue to use the oat but planned on trying a different route.. I have a 5000s to connect it too which does not require a special card for programming.. if you can get a hold of one that may be a easier way of doing it... did you have any luck with your project?
I also was planning trying to use the 8-relay module if possible as well.

 

[lovewestec5000]

Were you ever able to get a solution for the OAT?  I have the same problem.
 
Thanks

 

[ecborgoyn]

Old age is creeping-up on me.   I forgot that I posted about my 'project' regarding reverse-engineering the Westec OAT interface..  It's been a few years, but the project is still on the list, but close to the bottom.  But a couple of weeks ago I did think about resurrecting the project soon.  The OAT is still mounted on my garage overhead door frame.  And I would still like to get it working about.  Maybe this post will get me over the 'motivation hump'.  Still looking at an Arduino to talk to the OAT and probably provide a few contact-closure I/O's to the M1G.
 
Another long overdue project is selling/disposing of my W5K boards (except for the OAT interface board...).  As far as I know, the only failed item was one LED keypad terminal.  That was the motivation for the W5K -> M1G replacement.