Converter for Fanuc brushless encoders

[jmelson]

I now have a converter board for the Fanuc "red cap" brushless motors. These have a proprietary scheme for the commutation encoder, and can't be used with industry standard brushless drives. This converter uses the encoder signals to produce standard "Hall" signals for the servo drive.
See http://pico-systems.com/oscrc4/catal...products_id=29
for details of this product.

Thanks,

Jon

[usfwalden]

Great, so this board takes the fanuc red cap signals and outputs standard hall signals and differential encoder with index signals?

Does it come with instructions that have the pinout of the red cap connectors?

[Al_The_Man]

You will need the pin out of your particular encoder, with some exceptions, the majority of Redcap encoders have 2000/2500 5v differential signals, which can be passed through as-is, the 4 commutation pulses need to be identified.
I have not used Jon's interface but I understand he intercepts these pulses and converts to those required for BLDC.
There are some encoders to be aware of that are high resolution and these are 1v p-p sine wave signal.
If you post the encoder number here and the MS connector size, I have the Fanuc listing for encoder resolution.
Al.

[usfwalden]

Would you be able to figure it from the motor model number? I haven't bought the motor yet and don't want to until I know it will work.

Originally Posted by Al_The_Man You will need the pin out of your particular encoder, with some exceptions, the majority of Redcap encoders have 2000/2500 5v differential signals, which can be passed through as-is, the 4 commutation pulses need to be identified. I have not used Jon's interface but I understand he intercepts these pulses and converts to those required for BLDC. There are some encoders to be aware of that are high resolution and these are 1v p-p sine wave signal. If you post the encoder number here and the MS connector size, I have the Fanuc listing for encoder resolution. Al.

[Al_The_Man]

If you PM me an email add, I can send you what I have, unfortunately Fanuc use a whole raft of different part numbers for some reason?
Al.

[jmelson]

Originally Posted by usfwalden Great, so this board takes the fanuc red cap signals and outputs standard hall signals and differential encoder with index signals? Does it come with instructions that have the pinout of the red cap connectors?

It gets complicated. There are apparently at least THREE totally incompatible "red cap" encoder systems in use, and you can't tell the difference from a cursory inspection! The standard machine-tool brushless motor, where the motor nameplate is marked "Encoder: Pulse Coder" is the one that my converter is for. It typically has a 17-pin MS connector with a 20-29P insert.
There are also absolute encoders, and incremental encoders that produce the industry-standard Hall signals directly.

If you have a model number for the motor, I have a table (provided by "Al the man" who knows a LOT about these motors) which tells how to figure out the encoder type from the motor part #.

My converter handles 1500, 2000, 2500 and 10,000 pulse/rev encoders. I can give you a pinout for the 17-pin connector.

Jon