SSI absolute encoders and analog servos

The manual page says timer-num

Ok,

setp hm2_5i25.0.ssi.00.timer-number 1

Does work, but I will check if there is also timer-num parameter. Also there is a small typo with SSI pins. It says positon where should be position. ie pin positon.position


Tero

Typo in pins of SSI+sserial firmware. This is halcmd show pins output:

2 float OUT 1.118481e+07 hm2_5i25.0.ssi.00.positon.position
12 s32 OUT 11184810 hm2_5i25.0.ssi.00.positon.rawcounts
12 bit I/O FALSE hm2_5i25.0.ssi.00.positon.reset

All three lines have positon.xxxxx


Tero

Maybe the hal pins use the name in the ssi_chan_0=something config line
so if that's misspelled all the position pins will be

( there are no positon strings in the hostmot2 driver )

Yes you are correct it was my typo in the config line I had positon%24. Sorry about that. Now corrected. Here is output of halcmd show param

12 float RW 400 hm2_5i25.0.ssi.00.frequency-khz
12 u32 RW 0x00000100 hm2_5i25.0.ssi.00.positon.counts-per-rev
12 float RW 1 hm2_5i25.0.ssi.00.positon.scale
12 u32 RW 0x00000001 hm2_5i25.0.ssi.00.timer-number

So that is timer-number

Tero

Ok we have a reading. It seems encoder output is 32 bit binary. Some pics:

Reading seems to increase or decrease steadliy when scale head is moved in either direction. Thank you very much for help.

Tero

Related config:

loadrt hm2_pci config="ssi_chan_0=xencoder%32e

#SSI stuff
setp hm2_5i25.0.ssi.00.frequency-khz 400
setp hm2_5i25.0.ssi.00.timer-number 1
setp hm2_5i25.0.dpll.01.timer-us -100
setp hm2_5i25.0.ssi.00.xencoder.scale 10000


Tero

I do get randomly:

Data transmission not complete on channel... erros.

I have changed setp hm2_5i25.0.dpll.01.timer-us -100 to setp hm2_5i25.0.dpll.01.timer-us -150

But that does not help. Data is 32 bits at 400 khz. Any ideas?