Hardware Kill and Decel Request

[noah.leblanc]

The "RMP CCU Hardware Interface Specification" document says this about the hardware kill:
"+5V must be provided to Pin 3 of J8 continuously to prevent the CC from disabling the motor drives"

It then says this about the hardware deceleration request:
"The CC allows for a hardware control signal on pin 3 of J8; this signal is normally pulled low by a 10K
Ohm resistor. If this pin is pulled up to +5V then the system will immediately begin to decelerate...
...Conveniently, +5V is provided by the CC on pin 1 of J8, this allows the user to easily connect a
momentary type switch between pin 3 and pin 1 of J8 and control the deceleration request."

It seems like it's saying that +5V on pin 3 of J8 is needed to keep the motor drives running but will also trigger a decel request. We could use some clarification on this point. Thanks.

[Craig]

There is a mistake in the documentation

Section 3.1 "Hardware Kill" is correct:

The opto-coupler is powered up by Pin3 of J8. +5V must be provided to Pin 3 of J8 continuously to prevent the CC from disabling the motor drives. Conveniently, +5V is provided as an output from the CC on Pin 1 of J8. Therefore, it is possible to connect a normally closed switch between Pin 3 and Pin 1 to control the disable response and allows for the simple connection of an E-stop type button.

Under Section 3.2 is in-correct and should read:

"The CC allows for a hardware control signal on pin 2 of J8; this signal is normally pulled low by a 10K
Ohm resistor. If this pin is pulled up to +5V then the system will immediately begin to decelerate...
...Conveniently, +5V is provided by the CC on pin 1 of J8, this allows the user to easily connect a
momentary type switch between pin 2 and pin 1 of J8 and control the deceleration request.

The decel request is on pin 2 and the hardware kill is on pin 3.

Just as an FYI the board you have is a version AA board and the following applies.
***NOTE**** on early revision before rev (AB) the opto-couplers ran from +12V. Pin 3 required +12V and Pin 1 provided +12V. On these early boards it was not possible to run directly from the +7.2V battery.

However, the decel request will activate with any voltage between +5 and +12 on either version of the board.

[noah.leblanc]

Awesome. Thanks Nice touch with the emoticons by the way.

[noah.leblanc]

We've tried applying both +5V and +12V to pin 2 of J8 while the motors are running and it does not trigger a decel request. Sending a decel request command over the ethernet connection works but the hardware decel request doesn't. Is this something that was not yet implemented for our version of the board?

For now, we will be putting our own switch in series with the hardware kill switch but ideally we would like to use the decel request instead.

[phussey]

The hardware decel request is disabled in software for the version you have I will get you an updated version of the code.

[noah.leblanc]

Awesome! We weren't sure if we were just doing something wrong.