terminatation? 7i47s + heidenhain 602e

I'm seeing a lot of watchdog bites and other spurious pin enumeration glitches on hm2 initialization.

The most obvious problems center around quadrature count errors.

I have three Heidenhain interpolators connected on the first three quad encoder inputs of the 7i47s. Heidenhain specs. their quadrature output signals as TTL. Could there be a problem with the default 'termination' jumper settings.

Also, I'm seeing (rather less frequently) quad-count errors originating from the encoder interfaces of the 7i29 cards. These cards are not yet connected. Must the encoder inputs be tied down if they aren't connected to an actual encoder?

Thanks
_jC

A couple of things:

1. If you are having random enumeration errors with standard supplied bitfiles,
this likely indicates a problem in the FPGA or PC hardware so it would be best to
check with a known good bitfile like the SVST4_8 first (7I29sconnected only)

2. The 7I47 is a differential input only card it will not work with TTL inputs

PCW wrote:

2. The 7I47 is a differential input only card it will not work with TTL inputs

Hmmm ... OK. I had assumed ...

Mesa wrote:

The 7I47S is a 12 input, 8 output RS-422 interfface for Mesa’s Anything I/O series of FPGA interface cards.

and

Heidenhain wrote:

Incremental signals: Square-wave pulse trains Ua1 and Ua2 and their inverted pulse trains _Ua1 and _Ua2 (according to RS-422).

implied the devices were both rs-422 and compatible?





I am powering the HH-602e units from the 7i47. They require:
Power supply UP = 5 V ± 5 %
Current consumption (without encoder light source or output load) nb, looks like I need to consider a power supply for the scale illumination.
EXE 602E typ. 55 mA, max. 90 mA.

and have them connected like this

Is this not correct? Should the HH connected inputs to the 7i47s be terminated?

Is anybody here interfacing HH interpolators? How are they doing it?

Finally, what should the monitor LEDs be telling me?

Thanks
_jC
.

OK when you said 'TTL' I assumed that meant single ended,
as thats a common usage of the term TTL when applied to encoders.

The interpolators you have have differential outputs so should be fine with the 7I47

The combination of interpolaters and encoders may well draw more current than the
flat cable can supply, so I would supply separate 5V to the 7I47 (from the PC)

The LEDs should track the A,B and index signals of each encoder.

PCW wrote:

1. If you are having random enumeration errors with standard supplied bitfiles,
this likely indicates a problem in the FPGA or PC hardware so it would be best to
check with a known good bitfile like the SVST4_8 first (7I29sconnected only)

Bad news. With the daughter cards disconnected and using the SVST4_8 BIT file I still get the random enumeration errors. This was working before. I will try again booting from the 'stable' ISO. In case that fails I suppose that means my 5i23 is broken?

PCW wrote:

The combination of interpolaters and encoders may well draw more current than the
flat cable can supply, so I would supply separate 5V to the 7I47 (from the PC).

With respect to the 5 VDC power requirements. I already am powering the daughter cards externally. But I wonder about the ability of the 7i47 to power 3 HH interpolators and their connected glass scales. The maximum current required for a HH interpolator + HH scale is 220mA. The spec for the 7i47 states 'MAXIMUM POWER TO I/O CONNECTORS 800mA'. It does not mention if that is per connector, or all connectors combined. P2, P3 and P4 each host 3 8-lug phoenix connectors. Each of the 4 'encoder' 8-lug connectors incorporates a power source. Can the power source on these encoder connectors supply 220mA, up to a combined total of 660mA?

Once again, thanks for your support of my project!
_jC
.

About the random enumeration errors???

I am not quite ready to accecpt that this is a new hardware problem with my 5i23 board. I have tried the board in 3 separate computers (2 different models), booting from the stable ISO and from my kernel+git linuxCNC version with the following results.

The two identical Dell GX620 boxes when booting from the ISO enumerate the i/o pins correctly, but immediately thereafter pncconf hangs with a KeyboardInterrupt problem?

The third box, a Lenovo thinkcenter m55 (core2/ich7) works perfectly, with respect to enumeration and pncconf.

With my kernel and linuxCNC version both types of boxes give i/o pin enumeration errors. Randomly.

The non-deterministic nature of the enumeration leads me to believe this is some sort of software problem. Also that the Lenovo-m55 runs pncconf correctly from the ISO supports this being a software problem.

But what about KeyboardInterrupt problems with the stable ISO??? Has anybody else seen this. Why only the Dell boxes?

Thanks
_jC
.