Additional I/O (Both) for PMDX-126C w ESS and 107

[CNCRouter4fun]

Sure could use a few extra inputs and a few extra outputs.  PMDX-108 offers choice of inputs or outputs.  Is there a solution that would provide some of each? Can an input be used as an output or visa-versa? Thanks

[Steve Stallings]

If you have two ports connected  to the PMDX-126, then you can use the extra inputs
on J11 and the extra outputs on J5 of the PMDX-126.

The PMDX-108 boards are designed to work with the 8 data bits of a parallel port and
the parallel port standard only allows using all 8 bits in the same direction. You can
daisy chain a PMDX-108 board with the second port of the PMDX-126 which normally
only responds to the control bits and not the data bits.

If you are using an Ethernet SmoothStepper, you can drive both ports of the PMDX-126
and still have a third port to run a PMDX-108.

[CNCRouter4fun]

Steve,
Thanks for the reply. More detail: My machine has been operating as a large 3 axis gantry router with a fourth motor on the slave “A” axis.  I currently have 4 gecko 203V drivers daisy chained on two PMDX-134 motherboards.  I plan to add  additional axis’ and drives as I incrementally upgrade the machine to 4th and 5th axis.  I am currently upgrading the spindle to an ATC.  This requires four additional inputs, plus a low air pressure fault input.  (There is also a square wave signal available proportional to RPM that I don’t know how to capture, would be nice but not essential). The ATC also requires additional outputs to control air solenoid valves for tool change and taper cleaning.  Also have a solenoid for coolant/chip clearing, a z height probe, and use the charge pump.  I am combining all of the homing/limit switches (NPN proximity sensors), except the slave axis, to free up some inputs.  Having read the PMDX-126c manual in detail I believe I have identified all of the inputs and outputs available from the two parallel ports provided by the ESS. If I use the ABCD outputs I may have enough outputs now but these will not then be available for the step and direction signals for the extra axis.  I also probably need to use relays to drive the solenoid valves (3) from the outputs.  At he same time all of the inputs will be filled leaving no availability for additional sensors.  This has me looking at the 8 unused pins on the second parallel port which can be inputs or outputs. Would like to have four of each but the PMDX 108 and 109 boards are all inputs or all outputs. Questions:
 Is there a mixed I/O option or other alternative?
If I go with additional outputs, does the PMDX-109 have a manual or other installation info?
What is the feasibility or drawbacks to using an additional I/O device connected through the USB port simultaneous to the ESS/PMDX-126 for less time critical i/o?

[Steve Stallings]

The extra 8 signals on the second parallel port connection must all be inputs
or all be outputs. This is a legacy restriction related to how PC parallel ports
work. The computer cannot use them as a mixture, so the PMDX-108 and 109
are all inputs, or all outputs.

Oops, we never got the PMDX-109 manual created. It is a simple board and
you can read the PMDX-108-Output manual regarding connections and setup.

If you have an ESS it is possible to have two extra boards. One would be
connected as a daisy chain to the second parallel port of the PMDX-126 and
the other can connect to Port 3 of the ESS.