MESA 7i93 PWM question - motor rotation direction switch

Dear All,

I try to set up 7i93 PWM control for my ATC motor and I struggle with its rotation direction change, meaning:

- if pwmgen.0.value = positive number, pwm signal is on PIN6 as expected, motor rotates clockwise.
- if pwmgen.0.value = negative number, there is no PWM signal on PIN8, motor does not rotate at all.

I use PWM controlled mosfet bridge which expects CW and CCW input PWM signals on TTL level.
Regardless of pwmgen.output-type it does not work, but based on hostmot2 manual in my understanding it should work with output-type 2.
7i93's firmware is standard.

What do I wrong, or how can I change the rotation direction with PWM if my motor drive expects CW and CCW PWM signals?

thank you for your help.
Regards,
Tamas
 

What does:

mesaflash --device ethernet --addr [card_ip_address] --readhmid 

report?

 

Configuration Name: HOSTMOT2

General configuration information:

  BoardName : MESA7I93
  FPGA Size: 9 KGates
  FPGA Pins: 144
  Number of IO Ports: 2
  Width of one I/O port: 24
  Clock Low frequency: 100.0000 MHz
  Clock High frequency: 200.0000 MHz
  IDROM Type: 3
  Instance Stride 0: 4
  Instance Stride 1: 64
  Register Stride 0: 256
  Register Stride 1: 256

Modules in configuration:

  Module: DPLL
  There are 1 of DPLL in configuration
  Version: 0
  Registers: 7
  BaseAddress: 7000
  ClockFrequency: 100.000 MHz
  Register Stride: 256 bytes
  Instance Stride: 4 bytes

  Module: WatchDog
  There are 1 of WatchDog in configuration
  Version: 0
  Registers: 3
  BaseAddress: 0C00
  ClockFrequency: 100.000 MHz
  Register Stride: 256 bytes
  Instance Stride: 4 bytes

  Module: IOPort
  There are 2 of IOPort in configuration
  Version: 0
  Registers: 5
  BaseAddress: 1000
  ClockFrequency: 100.000 MHz
  Register Stride: 256 bytes
  Instance Stride: 4 bytes

  Module: QCount
  There are 4 of QCount in configuration
  Version: 2
  Registers: 5
  BaseAddress: 3000
  ClockFrequency: 100.000 MHz
  Register Stride: 256 bytes
  Instance Stride: 4 bytes

  Module: PWM
  There are 4 of PWM in configuration
  Version: 0
  Registers: 5
  BaseAddress: 4100
  ClockFrequency: 200.000 MHz
  Register Stride: 256 bytes
  Instance Stride: 4 bytes

  Module: StepGen
  There are 4 of StepGen in configuration
  Version: 2
  Registers: 10
  BaseAddress: 2000
  ClockFrequency: 100.000 MHz
  Register Stride: 256 bytes
  Instance Stride: 4 bytes

  Module: LED
  There are 1 of LED in configuration
  Version: 0
  Registers: 1
  BaseAddress: 0200
  ClockFrequency: 100.000 MHz
  Register Stride: 256 bytes
  Instance Stride: 4 bytes

Configuration pin-out:

IO Connections for P2
Pin#                  I/O   Pri. func    Sec. func        Chan     Sec. Pin func   Sec. Pin Dir

 1                      0   IOPort       QCount           1        Quad-B          (In)
 3                      1   IOPort       QCount           1        Quad-A          (In)
 5                      2   IOPort       QCount           0        Quad-B          (In)
 7                      3   IOPort       QCount           0        Quad-A          (In)
 9                      4   IOPort       QCount           1        Quad-IDX        (In)
11                      5   IOPort       QCount           0        Quad-IDX        (In)
13                      6   IOPort       PWM              1        PWM             (Out)
15                      7   IOPort       PWM              0        PWM             (Out)
17                      8   IOPort       PWM              1        Dir             (Out)
19                      9   IOPort       PWM              0        Dir             (Out)
21                     10   IOPort       PWM              1        /Enable         (Out)
23                     11   IOPort       PWM              0        /Enable         (Out)
25                     12   IOPort       QCount           3        Quad-B          (In)
27                     13   IOPort       QCount           3        Quad-A          (In)
29                     14   IOPort       QCount           2        Quad-B          (In)
31                     15   IOPort       QCount           2        Quad-A          (In)
33                     16   IOPort       QCount           3        Quad-IDX        (In)
35                     17   IOPort       QCount           2        Quad-IDX        (In)
37                     18   IOPort       PWM              3        PWM             (Out)
39                     19   IOPort       PWM              2        PWM             (Out)
41                     20   IOPort       PWM              3        Dir             (Out)
43                     21   IOPort       PWM              2        Dir             (Out)
45                     22   IOPort       PWM              3        /Enable         (Out)
47                     23   IOPort       PWM              2        /Enable         (Out)

IO Connections for P1
Pin#                  I/O   Pri. func    Sec. func        Chan     Sec. Pin func   Sec. Pin Dir

 1                     24   IOPort       StepGen          0        Step/Table1     (Out)
 3                     25   IOPort       StepGen          0        Dir/Table2      (Out)
 5                     26   IOPort       StepGen          0        Table3          (Out)
 7                     27   IOPort       StepGen          0        Table4          (Out)
 9                     28   IOPort       StepGen          0        Table5          (Out)
11                     29   IOPort       StepGen          0        Table6          (Out)
13                     30   IOPort       StepGen          1        Step/Table1     (Out)
15                     31   IOPort       StepGen          1        Dir/Table2      (Out)
17                     32   IOPort       StepGen          1        Table3          (Out)
19                     33   IOPort       StepGen          1        Table4          (Out)
21                     34   IOPort       StepGen          1        Table5          (Out)
23                     35   IOPort       StepGen          1        Table6          (Out)
25                     36   IOPort       StepGen          2        Step/Table1     (Out)
27                     37   IOPort       StepGen          2        Dir/Table2      (Out)
29                     38   IOPort       StepGen          2        Table3          (Out)
31                     39   IOPort       StepGen          2        Table4          (Out)
33                     40   IOPort       StepGen          2        Table5          (Out)
35                     41   IOPort       StepGen          2        Table6          (Out)
37                     42   IOPort       StepGen          3        Step/Table1     (Out)
39                     43   IOPort       StepGen          3        Dir/Table2      (Out)
41                     44   IOPort       StepGen          3        Table3          (Out)
43                     45   IOPort       StepGen          3        Table4          (Out)
45                     46   IOPort       StepGen          3        Table5          (Out)
47                     47   IOPort       StepGen          3        Table6          (Out)

 

Are you sure you have the pinout correct?

PWM 0 uses 50 pin connector pins 15,19,23

yes, I meant pin numbers as they are shown in the I/O column, but you are right I had a mistake as I tried to configure pwm1, but I experienced the same behavior with pwm0 on i/o pins 7 and 9.
if I use multimeter I see between 2,5..4V signal on pin6 (depends on the value, of course) but nothing on pin8. (corresponding 50pin numbers are 13,17)
/enable signals work properly.
thx

Does DIR change in output type 0?

(maybe there's a hardware issue)
 

not with type 0, I couldn't set it but with type 1 works (I mean, logic level of the corresponding pin changes properly)
so I think there is no hardware issue.

Sorry I meant mode 1 (there is no mode 0)

This is pretty odd. I can't duplicate this here. I tested by putting a couple LEDs on the
PWM/DIR lines and in output mode 2 the PWM output changes from the PWM pin to
the DIR pin when the PWM value is negative. In addition, the LED brightness was proportional
to the absolute PWM value as expected.

Its especially odd since the PWM module is unchanged since it s original creation (version 0)
and PWM output mode 2 is used on some of our interface cards (7I48,7I49)

What LinuxCNC version? 


 

2.9.4
OK, thanks for your confirmation that this should work. I have another 7i93 in production, I'll check with that and come back with the results.