motorola centracom basics/basic questions

[F16F35F14F18]

hello, i would like to learn more about the motorola centracom dispatch systems.

(1) how did it interface with conventional, digital and trunking systems?
(2) what is the bare mininum for a centracom to operate?
(3) what did a typical centracom dispatch system rack look like (device model numbers, where routers/computer/radios/specialized devices/ present?)
(4) what/were any software components and what did they do?
(5) what is the difference between centracom 1 and 2 vs centracom "elite"
(6)when was centracom dispatch units in use?
(7)what equipment was present at a desk/control panel/operators station?
(8)other general information.

 

[xmo]

For a nostalgia trip - Centracom back in the day (before CCII)

 

[xmo]

Here you go:

 

[ElroyJetson]

I am by no means an expert on the subject or even a reasonably competent centracom technician. I can, however, tell you that the subject of Centracom consoles and equipment, in all their various series and types and configurations, is a HUGE topic.

There are, I'm sure, people who built their careers working ONLY on Centracom console systems and equipment, and never even TOUCHED the radios they interface with.

At one point I had two Centracom desktop consoles, cute little things that had 8 channel modules each, and I wanted to hook one up to...SOMETHING...and so I started doing some digging. Ended up selling them on ebay because I soon realized that it was too much work and too much scarce equipment to find before I'd have a prayer of making it work. If I thought it'd be as simple as connecting a few tone or DC remotes, I soon found that I needed to think again.

I wish you great luck and success. But you've chosen a complex and difficult project.

 

[RFI-EMI-GUY]

I started my career, May of 1976 working final test at the factory on these beasts. Centracom "one". It was quite an education. All discrete components and RTL, DTL, logic mixed with all flavors of analog amplifiers, compressors, tone generators and other doodads. When stuff is assembled manually into the PCB, troubleshooting is more often a wrong part, part reversed, cold solder. Almost never a bad component, except the VU meters, for some reason the same bad VU meters kept getting recycled one month. Sometimes the engineers would do a Special Product. That could be challenging to sort out. But mostly they worked and it was merely a matter of adjusting levels and testing distortion.

 

[F16F35F14F18]

Here you go:

so is centracom "elite", "gold" "1" and "2" separate product series or?

Here you go:

and then for the 19" card cage, is this something like it?

For a nostalgia trip - Centracom back in the day (before CCII)

around 20 years before i was born, so not necessarily nostalgia, this stuffs awsome though.

View attachment 147594

I started my career, May of 1976 working final test at the factory on these beasts. Centracom "one". It was quite an education. All discrete components and RTL, DTL, logic mixed with all flavors of analog amplifiers, compressors, tone generators and other doodads. When stuff is assembled manually into the PCB, troubleshooting is more often a wrong part, part reversed, cold solder. Almost never a bad component, except the VU meters, for some reason the same bad VU meters kept getting recycled one month. Sometimes the engineers would do a Special Product. That could be challenging to sort out. But mostly they worked and it was merely a matter of adjusting levels and testing distortion.

well it seems i should be able to troubleshoot any of this old equipment if i find any, i have some experience in electronics assembly and troubleshooting.

Here you go:

is this the backplane described in the document you sent (thanks by the way) (part number:

BLN6648A318

 

[ElroyJetson]

If you do pursue the project and make some headway, please do feel free to make a separate topic on it and update it as you make progress. You'll have people who follow it with interest, myself included.

Personally I think something is lost when you move away from a dedicated hardware console and replace it with a monitor, keyboard, mouse, and software. I like physical buttos, knobs, dials, and indicators.

If I had an unlimited budget to build the ultimate radio/test and measurement facility, I'd want to use Centracom consoles for the bulk of the fixed frequency stations.

That'll have to wait for a really good lottery win.

 

[wa8pyr]

so is centracom "elite", "gold" "1" and "2" separate product series or?

Sort of. Centracom 1 was the original and a totally separate product line. It did not use a CEB, all the interfacing was done at the console.

Centracom II started out with the traditional "buttons and LEDs" operator position (freestanding or desktop), and morphed into the CRT desktop, the computer-based Elite desktop, and then the Gold Elite. All of the Centracom II line used the CEB to interface to the outside world.

At one point I had two Centracom desktop consoles, cute little things that had 8 channel modules each, and I wanted to hook one up to...SOMETHING...and so I started doing some digging. Ended up selling them on ebay because I soon realized that it was too much work and too much scarce equipment to find before I'd have a prayer of making it work. If I thought it'd be as simple as connecting a few tone or DC remotes, I soon found that I needed to think again.

I wish you great luck and success. But you've chosen a complex and difficult project.

What he said. I once had a small part of a Centracom 1 in my shack; while it was a bear to maintain, it was a lot easier than a Centracom II or Gold Elite, thanks to everything being in one place and using mostly discrete components (and no surface-mount stuff).

Each module in a Centracom 1 console (such as that pictured above) had to be specifically chosen for the particular type of interface to the radio it was going to control; a radio no more than 50-100 feet away from the console could use DC remote, while a radio located farther away had to use tone remote to avoid erratic operation due to noise on the line.

Motorola improved on that with the Centracom II line. You had anywhere from one to a dozen operator positions (consoles) in the dispatch room, while in the back room you had the CEB (pronounced "seeb"). It's been years, but if I recall correctly the CEB contained BIMs (Base Interface Module, for interface to a conventional tone-remote radio), TIMs (Trunking Interface Module, for interface to a trunked system), and CIMs (Console Interface Module, for interface to an operator position), along with the necessary power supplies. It's been so long I may be off on some of those acronyms...

Assuming you're thinking conventional (don't even go down the trunking rabbit hole, as it requires a direct connection to the trunked system), in addition to the console you'll need the 7' rack containing the guts: power supplies, a BIM for each radio you want to hook up, and a CIM for each operator position. And all the cables, wires and doodads needed to hook it all together.

Elroy is right; making one of these work is complex and difficult.

HOWEVER.... there are some desktop consoles out there which contain all the guts in the desktop unit; Motorola made one (CommandStar Lite, I think) and Zetron made their System 4000 version. There's still quite a bit of work required but not nearly as much as would be needed with a Centracom console; in a nutshell you just connect your tone-remote radios to it and have a ball.

 

[NVAGVUP]

Per above. Centracom utilized T/R modules. Think tone remote on a PC board. A standard op was 8 T/R modules. If it was DC control, I believe there was a daughter board that had to be installed. The last one I supported had 2 operator positions (8 T/R's per OP) After a direct stroke of lightning, 3 T/R modules were left standing out of 16 possible. After a day of replacing switching diodes and transistors, we had 8 modules running. Eventually got all modules operational, but never was reliable again. Happy to see it go. Went to Centracom Gold. CEB based Centracom was extremely reliable. I think I installed/supported 5 CEB's and ~ 23 OP's. Slept well at night.

 

[RFI-EMI-GUY]

(5) what is the difference between centracom 1 and 2 vs centracom "elite"

Centracom "one" used discrete TR channel modules to connect to the base station equipment. A base station was connected vi 2 wire or 4 wire leased copper lines. Older base stations used a DC current imparted on the copper lines to control PTT/Monitor?Channel selection. Later base stations used tones for control that were sent at beginning of each transmission. A guard tone of 2175 Hz held up the transmitter while talking. The tone was filtered out at the base station. Each console operator position that had access to that base station had a corresponding TR module. Tone remote control facilitated connection of base stations by microwave sites.

Centracom two used shared TR channel modules, called BIM's (Base interface module) mounted in a CEB (Common Electronics Bank) and each operator position could access any of the BIM's using Time Division Multiplex on a shared bus. In many cases a redundant BIM was provided so that a BIM failure would not affect all of the console positions. Base station connectivity options were similar to CC 1 .

Trunking required CC 2 consoles and in that case TBIM's Trunking BIM's interfaced each of the trunking base stations and the allocation of a TBIM to a talk group, and thus a talk group on the console position. The trunking controller managed these virtual connections.

 

[saber2k5]

The CEB was the Central Electronics Bank.

 

[RFI-EMI-GUY]

The CEB was the Central Electronics Bank.

I spent my post Motorola days writing generic procurement specs so the "common" creapt in as a generic term.

 

[Lucifer_Morningstar]

I am by no means an expert on the subject or even a reasonably competent centracom technician. I can, however, tell you that the subject of Centracom consoles and equipment, in all their various series and types and configurations, is a HUGE topic.

There are, I'm sure, people who built their careers working ONLY on Centracom console systems and equipment, and never even TOUCHED the radios they interface with.

At one point I had two Centracom desktop consoles, cute little things that had 8 channel modules each, and I wanted to hook one up to...SOMETHING...and so I started doing some digging. Ended up selling them on ebay because I soon realized that it was too much work and too much scarce equipment to find before I'd have a prayer of making it work. If I thought it'd be as simple as connecting a few tone or DC remotes, I soon found that I needed to think again.

I wish you great luck and success. But you've chosen a complex and difficult project.

Surprised none of the CC console "gray beards" haven't chimed in.

This is what you do (analog only) - "high level" outline:
1. Go on that auction site - get the following
a. Centracom card cage (and power supply).
b. Get a BLN7011 timer card, you can get by with one.
c. Get a BLN6654 BIM card for each tone control base you want to work with.
d. Get a COIM (can't recall the part #) - this is for your console Op position.
e. Get a BLN6755 RS-232 card (you'll need it to program the COIM).
f. Get a Centracom "Buttons & LED" Compact Console (with power supply).

2. Get a 66 punch block with standard cable (to connect to the card cage backplane)
the 4 wire base will connect to the punch blocks. Refer to manual for pinouts.
3. Get Centracom II+ RSS (without this you cannot program the COIM) - it's out in the wild.
4. Fabricate the cable (pinouts in manuals) to connect the cardcage to the Console.
(if you're lucky, one will be on that auction site - it's a funky connector).
5. Refer to manual for card cage slots to insert the cards into.
6. Fire up Centracom II+ RSS (on a DOS machine), fabricate cable to connect COM1
to an RJ45 connector - that's on the BLN6755 RS-232 card, plug card into half slot
above the COIM.
7. Using Centracom RSS, create a new console config to match the physical layout
of Compact Console CCM's (channel control modules), and options (ie F1, F2, etc).
Normally, this step is unique to a customer, it'll be created by the CCSi engineer
depending on what was ordered. In this instance, you're working backwards to
match what's already present in the physical console.
8. "Export" it (these are in the RSS screens).
9. Do a "MUPL" - where you dump the config into the COIM via the RS232.
10. Reset the COIM (side panel button), reset BIM's (hear the cool tones over
the wireline).
11. Offer thanks it's not a 6809 OMI that had an EPROM you need to use a UV
eraser on, and a ZIF socket "shooter".
12. Refer to manuals , you'll need to clear the dots on the primary RCM, then
set the clock....been awhile... diag 12, shift AB ? ... or vice versa.. check manuals.
13. The RS232 can also connect to a terminal emulator (again see manuals). It's
not necessary for operation.
14. Might want to check BIM output levels (typically set to -6 dBm, but have
seen -10 dBm).. depends on if it's dumped to microwave or wireline, etc.

You should now have a working console, albeit - with the physical layout of the
surplus Centracom Compact console. If you get lucky, you might find one with
DCCM's (Display Channel Control Modules), that can control multiple bases of
one CCM - and they look cool with the red dot matrix LED display.

No need to concern oneself with Embassy switches, AEI's, LORI's, mux-bus,
DPI's, MGEG's, blah, blah, blah.....above is just a simple tone control one
Op position set up for an analog 4 wire base (MSF5000, Quantar, MTR2000, or
even a Consolette w/TRC).

If a DIU can be sourced, you could create a digital channel - although the
DIU connection would be V.24 (not IP based), will also need a BLN1215 ACIM
card to have digital functionality, and the base would need the firmware to
support digital.

No warranty expressed or implied.
No further support will be provided.
Good luck.

 

[ElroyJetson]

I remember now, I had two of the "Dispatcher" mini consoles, I think they were good for up to 8 channels each.

Even those were more of a hassle to hook up than I wanted to deal with.

 

[RFI-EMI-GUY]

The Centracom furniture was always very nice .
Great for ham shack, if you have that kind of space.

 

[davidgcet]

and with a few card changes(and a LOT o programming) a CCII could be upgraded to a Gold Elite CRT or Buttons and LEDS. you needed CRT to really do trunk groups, but B&L was supported if the user was comfortable with everything having to be hard coded. i never programmed a CCII, but when one customer got a GE B&L i was informed i needed to load up a computer with NT 4.0 and start learning because I was to be the optimizer. i was a fun task to learn, i had already done CRT models for a couple other customers but in those cases a Moto ST did the original programming and i only had to make changes later as needs changed or TGID were added.

 

[F16F35F14F18]

thanks everyone! if i have more questions i will prefer to circle back to this thread, providing it isnt closed. opening a new thread, motorola type 2/smartnet with the same questions in mind.

 

[y85csm]

The console card could be a OMI, TOMI, or COIM.
OMI needs PROM burner
TOMI is a Turbo OMI and could be either PROM burner or RSS programmed depending on vintage.
TOMI is what most CCII+ Centracoms used.
COIM is the Gold Elite version.

OMI and TOMI require the AEB (audio expansion board) to handle the audio.
COIM has the audio stuff all on the same board.

Besides all the complexities in putting together a Centracom in general, I give you a big heads up.
All this stuff is OLD!!
A lot of my customers that tried to keep this stuff running after EOL had to change the capacitors on the boards to keep them running.
FYI

 

[y85csm]

Oh, by the way:
BIM is for conventional bases.
TBIM were for Smartnet trunking and had a dual LOBL daughter card.
ZBIM were for SmartZone and had a loopback on the audio lines.
All can be converted to regular BIMs.

 

[KevinC]

LOBL, LOMI. BIM….stop it. You’re bringing back bad memories.