SSI absolute encoders and analog servos

Did you find an example for me?


Tero

The config line for the Siemens encoder is this

ssi_chan_0=position%24ge

Meaning 24 bit (g)ray (e)ncoder
(see Hostmot2 manual page)

Here are some minimal setup

setp hm2_5i25.0.ssi.00.frequency-khz 400
setp hm2_5i25.0.ssi.timer-number 1

In addition, the dpll must be set up to start the ssi data transfer before LinuxNCNC read function is called

setp hm2_5i25.0.hm2dpll.01.timer-us -100

(assuming 100 usec is enough for the worst case transfer, 24 bits at 400 KHz is about 63 usec so ok in this case)

Ok, thank you. I will try my best to get this working either tomorrow or monday.

Tero

I get:

Found file(REL): ./core_sim4.hal
./core_sim4.hal:15: parameter or pin 'hm2_5i25.0.ssi.timer-number' not found

Show pin gives:

12 float IN 100 hm2_5i25.0.dpll.01.timer-us
12 float IN 100 hm2_5i25.0.dpll.02.timer-us
12 float IN 100 hm2_5i25.0.dpll.03.timer-us
12 float IN 100 hm2_5i25.0.dpll.04.timer-us
12 float IN 1.000063 hm2_5i25.0.dpll.base-freq-khz
12 u32 OUT 0x0000002A hm2_5i25.0.dpll.ddsize
12 float OUT 13.26796 hm2_5i25.0.dpll.phase-error-us
12 u32 IN 0x00400000 hm2_5i25.0.dpll.plimit
12 u32 OUT 0x00000008 hm2_5i25.0.dpll.prescale
12 u32 IN 0x000007D0 hm2_5i25.0.dpll.time-const
12 u32 OUT 0x00000000 hm2_5i25.0.sserial.port-0.fault-count
12 u32 OUT 0x00000001 hm2_5i25.0.sserial.port-0.port_state
12 bit IN TRUE hm2_5i25.0.sserial.port-0.run
12 u32 OUT 0x00000000 hm2_5i25.0.sserial.port-1.fault-count
12 u32 OUT 0x00000001 hm2_5i25.0.sserial.port-1.port_state
12 bit IN TRUE hm2_5i25.0.sserial.port-1.run
12 bit OUT FALSE hm2_5i25.0.ssi.00.data-invalid
12 s32 OUT 11184810 hm2_5i25.0.ssi.00.positon.count
12 bit I/O FALSE hm2_5i25.0.ssi.00.positon.index-enable
12 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

Ẁhat is wrong?

Tero

If it should be hm2_5i25.0.encoder.00.timer-num there are no hm2_5i25.0.encoder pins at all.


Tero

Nope it did not work either.


Tero

Its a parameter:
(s32 r/w) hm2_XiXX.N.ssi.MM.timer-num
This parameter allocates the SSI module to a specific
hm2dpll timer instance. This pin is only of use in
firmwares which contain a hm2dpll function and will
default to 1 in cases where there is such a function, and
0 if there is not. The pin can be used to disable reads
of the encoder, by setting to a nonexistent timer number,
or to 0.

So this line should be "setp hm2_5i25.0.ssi.00.timer-number 1"