Hi,
I can't see any spec for it either. I do see that the upper board logic supply needs be capable of 0.1A. Clearly the outputs are logic level,
I wouldn't consider asking an output to sink more than 5mA, the risk of blowing it up is too high.
The Estop terminal on my BoB is logic high by virtue of 5V being applied through the series of normally closed contacts of my limit switches
to the Estop terminal with a 5k resistor from the same terminal to earth. Thus with all contacts closed 5V is applied directly to the pin, when
one or more contacts are open the 5V continuity is lost and the 5k resistor pulls the pin logic low and Estops Mach. If I were to hook the output
pin of a servo drive such as your TK 10 to the Estop in addition to the limit switch circuit it would fail. The 5V of the limit switch circuit would
attempt to hold servo drive pin high even when the pin was trying to go logic low, it would try to sink a lot of current and fail and damage the drive.
You'll need to introduce some resistance in the 5V supply to your limit switch string. If you put 5K in there with the limits all closed logic high would
only be 2.5V by virtue of the voltage divider formed by the 5k resistance to earth at the Estop pin, such a low logic high could render your Estop
noise sensitive. If you reduce the series resistance to 1k then the current to be sunk by the servo pin would be 5mA and yet have a logic high of
4V, acceptable. I would in addition put a diode in series with the servo pin so that if in fact its voltage goes higher, 12V say, it cannot blow your
Estop pin of you BoB if as in my case your BoB is a 5V device.
Craig