Any Idea

[Mark-]

No, even an ON green battery LED means low battery.

I accept you have seen every piece of equipment, ever created, with a battery state indicator LED.

 

[CENTER]

I've got to say that I have been around PLC's a long time and that's the way every one I have seen worked.

 

[Mark-]

I've got to say that I have been around PLC's a long time and that's the way every one I have seen worked.

Ditto, all kinds of PLCs, special built controllers, controllers for a task (fire or fire/gas detection monitoring, etc.), pump skids, turbine controls, kilns, BMS (building and boiler), BTU controllers/totalizators, combustion controls, etc.. I recall one controller that had "Batt OK" on the label. Green OK, off not OK. IIRC, it could have been an old Honeywell controller.

 

[JesperMP]

My guess was that the "BATTERY" led indicates low battery, since it is red.
Now I notice that the "CPU OK" is also red. So red can mean OK !
Then on the other hand, since it is does not say "BATTERY OK", but only "BATTERY" then I deduce that the meaning is that the battery is not OK.

By the way, this controller is weirdly arcaic, but the company still exist, the controller is still their main product, you can get manuals off their site, and there is even a software (which you can buy ?) for connecting to the controller via a modem.

 

[JesperMP]

In the manual it says:

BATTERY Light:
On = Clock Battery OK
Off = Clock Battery Low

So me deduction was wrong !

and

BATTERY LIGHT
The BATTERY light is on when the time/date clock backup battery voltage is ok. This battery is only used to power the time of day and date clock chip when the 120 Vac power is removed from the Chief Dispatcher. When new, the battery can power the clock for approx. 2 years with 120 Vac Power removed. The clock battery has a shelf life of approximately 8 years (with 120 Vac applied).
The battery is located under the plastic guard on the lower door.
Blockware is stored in non-volatile flash memory. This battery is not used to retain the blockware memory.

 

[Mark-]

In the manual it says:
BATTERY Light:
On = Clock Battery OK
Off = Clock Battery Low

Thanks.

I have been involved, on the team, in the development for several embedded controllers over the years. I recall many years ago all LEDs had to be red, regardless of what the LED indicated, because red was the lowest cost LED. HA

 

[JesperMP]

I have been involved, on the team, in the development for several embedded controllers over the years. I recall many years ago all LEDs had to be red, regardless of what the LED indicated, because red was the lowest cost LED. HA

Yeah. And also NPN inputs because that is (was) a tiny tiny bit less expensive than PNP.

Nowadays, when you open a control cabinet and see a red lamp, that indicates there is a problem.

 

[Nova5]

Actually a Battery LED On means the battery is low, or in this case completely dead after 45 years.




And after 45 years:

Varies by design. ON Good is just as viable as ON Bad. it was more a surmised guess based on the other lights. Flashing would be a much better indicator for Bad than On or Off. grab attention. But as seen a few posts later. On = Good.

 

[g.mccormick]

Preferred Instruments
https://www.preferred-mfg.com/produ...ems/chief-dispatcher-boiler-plant-master.html

Your Google-fo must be very strong to find that. Good job.

 

[plvlce]

I have seen far more ON bad for batteries than the opposite. I don't mind ON good, but I much prefer it to be labeled 'Battery OK' to eliminate confusion, especially if it's red.

Of course originally there were not the standards (formal or informal) we have now, and often newer systems simply copy what their direct predecessors did without considering how that compares to general industry practices.

 

[CENTER]

Preferred Utilities has excellent customer service. Sent them the pictures, they identified unit and sent me this response. Guess I was wrong. Sorry didn't see you posted the same thing.