HURCO KMB-1 Control Update

Hi,
A while back I obtained this great condition mill, and spent a good while getting the original B control and parajust vfd to function. I guess I've had a good few years of use, and learned all that old school stand at the control panel block entry programming system. Thank goodness for CAD systems making it simple to workout profile tangent points and arc centres. What I have learned is the the machine is good, but  for programming prototype parts a bit of a liability, especially if you make changes in the middle of 100 block programme. Not smashed anything, but embarrassed myself.

Always did have a plan to retrofit the control, but now is the time to do it. I know that these old machines have been covered a few times in the forum, but the questions I am bumping into don't seem to be quite covered hence the reason for a new Topic.


My plan is to insert a chassis containing some Mesa boards, and a Raspi 5 in and to make an intermediary interconnection board that accepts all the Hurco edge connectors that go to the B control. From the picture you'll  I've done most of the preparation already. 
The Mesa boards are 7i92T, 7i77D and 7i73  

The sub board accepts the original connectors, and breaks out into solder pads where I can add appropriate wires to connect into the Mesa items. 
My maybe silly idea on this, is that if I don't cut any wires, I can always revert to the historical system, to prove to anyone's  passing grand kids that there is life still in 1980's computing.

I'd like also to use the pots and original pulse generator retained in place in the pendant panel, as well as as the still working fvd and servos etc, in fact everything that's operational and can work with linuxcnc. ( I accept that the encoders will need many more lines and have 2000 cpr ones in stock.)

Question 1 Limit switches
The existing ones are 5volt solid state devices, and the output floats at 5volts, pulled up by a 470ohm resistor in the Hurco control, until triggered where it falls to zero and switches on an LED in an optical isolator which signals the servo to stop as well as telling the operating system that the axis travel has been exceeded.

My initial idea was to connect this output into the 7i77, but I now believe that the field IO terminals TB7/8 won't trigger at only 5 volts, so I propose to use the 7i73 P2 connector, pins IN8 thru' IN15 which are 5 volt tolerant, but with 4.7 kohm pull up resistors.

I'm not the greatest at electrics, so would appreciate your advice.

Thanks

Another option for reading 5V signals is spare 7I77 encoder input pins
These have the advantage of being better protected than 7I73 inputs
(to +-25V intermittant)

Ah, I hadn't realised that was an option.
Thanks

A while ago, JT gave me these instructions to a get a full list of pins for the 7i95 I was using with a 7i83.

In a terminal
halrun
loadrt hostmot2

(for ethernet)
loadrt hm2_eth board_ip=10.10.10.10
In another terminal
halcmd show all hm2 > pins.txt
This listed items like :- hm2_7i95.0.7i83.0.1.analogena0
ie the two cards are named.

With my three new boards (7i92-7i77-7i73) connected up, apparently alive as lights are on each one, I only get a list of the 7i92 pins.
Have I broken something?

Do you have 7I77 firmware loaded in the 7I92?

Does the 7I77 have 5V and field power?

I didn't load a firmware, because I couldn't see one that includes the 7i73 or one that seemed to be just for a 7i77.

I have 5 volts, but not field power.

For a 7I77 and a 7I92:
7i92_7i77x2D.bit

For a 7I77 and a 7I92T:
7i92t_7i77x2d.bin

7I77 digital I/O pins will now appear without field power.
Sserial expansion card (like the 7I73 or 7I84) do not require specific
firmware.
 

Marvellous, all present and correct now.
(I've a 7i92T)

Many thanks

I've failed to work out how to use a spare encoder input on the 7i77 as a Limit switch input.
I've started out by telling PNCConf that the switches are connected to the I/O Field inputs so I can see the syntax, for instance 
net min-x     <=  hm2_7i92.0.7i77.0.0.input-00     for the X limit minus.
Was planning then to edit this line to match an encoder.

But when I study the hal file posted here, I cannot see how the encoder input pins are called. I was expecting there to be similar 7i92..7i77 references in the Joint 0 section for instance and there are for the analogue outputs, but not against the encoders.
Can you help please.
Thanks

The raw encoder pins have names like:

hm2_7i92.0.encoder.03.input-a
hm2_7i92.0.encoder.03.input-b
hm2_7i92.0.encoder.03.input-index