Mesa 7i48 servo card - no input signal.

I cannot get any data from my Mesa servo card 7i48. I'm learning Hal not 2-3 hrs like someone said, but 2-3 days is more like it. I can see the signals going into the card, I can see them on the chip pins on the card but there is no output on the chips. It looks like the chips enable is set to false. I cannot see how to change this manually with Hal. All the inputs enables are common to the cards enable line which is pin one on the ribbon connector. Any idea on how to set the servo cards enable with Hal.

The signal name is /ENA0

The HAL enable signal for the 7I48 analog outputs would be [card-driver-prefix]pwmgen.00.enable

Where 'card-driver-prefix' depends on the FPGA card and possibly how many FPGA
cards are installed

We only have one FPGA card. I've just realized that the /ENAO is an output so been chasing the wrong thing. I guess this is a MESA question as to why I cannot get any signals through the 7I48 card. I've tried both the TTL and RS422 options.

It was not possible to tell from you original question what signals you were talking about.

Since you mentioned /ENA0 I assumed you meant that you could not get analog output from the 7I48 card.

If the encoder inputs do not work, most likely problems are:

1. Wrong FPGA configuration file (not suited to 7I48)
2. 7I48 connected to wrong FPGA connector
3. No power to 7I48
4. Encoder --> 7I48 wiring or 7I48 --> FPGA card flat cable issues

I've been looking at the inputs on the Chips on the 7I48 card. They are DS26L32 which is a QUAD Differential Line Driver. I can see signals going in but nothing coming out. The have an enable line which I mistakenly though was the /ENAO.

a couple questions:

What FPGA configuration file are your using?
What FPGA card connector is the 7I48 connected to?

The signals from the 7I48 to the FPGA card are not straight encoder signals but rather
multiplexed signals from 2 encoders, but for this multiplexing to work correctly you need the correct FPGA configuration

Th FPGA is a 5I20.
I'm not sure how to find the Config File.
New to this ?


Note at a chip level, I'm not getting a signal.

I would suggest that you _not_ poke around at the chip level until you verify that there is actually a problem reading encoders with the proper configuration file and 7I48 --> FPGA connection.

The firmware (configuration file) selection is normally in the .ini file, something like this:

CONFIG="firmware=hm2/5i20/7i47s.bit num_encoders=1 num_pwmgens=1 num_stepgens=4"

(this is NOT the configuration you want)

Thanks for the quick replies. Very helpful thanks.

In the Lathe_Copley.HAL I have

loadrt hm2_pci config="firmware=hm2/5i20/SVST8_4.BIT num_encoders=3 num_pwmgens=3 num_3pwmgens=0 num_stepgens=0 "

Thanks Wallace

Here are the files