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6i25 + 7i85 - BISS-C, hm2dpll timing

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4 years 9 months ago #231642 by rumking
6i25 + 7i85 - BISS-C, hm2dpll timing was created by rumking
Hi guys,
I am trying to get working a BISS-C encoder on 6i25+7i85 combo. I created a bitfile myself, which looks like this:
Code:
sudo mesaflash --device 6i25 --readhmid Configuration Name: HOSTMOT2 General configuration information:   BoardName : MESA6I25   FPGA Size: 9 KGates   FPGA Pins: 144   Number of IO Ports: 2   Width of one I/O port: 17   Clock Low frequency: 66.6667 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: 66.667 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: 66.667 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: 66.667 MHz   Register Stride: 256 bytes   Instance Stride: 4 bytes   Module: MuxedQCount   There are 6 of MuxedQCount in configuration   Version: 4   Registers: 5   BaseAddress: 3600   ClockFrequency: 66.667 MHz   Register Stride: 256 bytes   Instance Stride: 4 bytes   Module: MuxedQCountSel   There are 1 of MuxedQCountSel in configuration   Version: 0   Registers: 0   BaseAddress: 0000   ClockFrequency: 66.667 MHz   Register Stride: 256 bytes   Instance Stride: 4 bytes   Module: SSerial   There are 1 of SSerial in configuration   Version: 0   Registers: 6   BaseAddress: 5B00   ClockFrequency: 66.667 MHz   Register Stride: 256 bytes   Instance Stride: 64 bytes   Module: StepGen   There are 5 of StepGen in configuration   Version: 2   Registers: 10   BaseAddress: 2000   ClockFrequency: 66.667 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: 66.667 MHz   Register Stride: 256 bytes   Instance Stride: 4 bytes   Module: BISS   There are 1 of BISS in configuration   Version: 0   Registers: 4   BaseAddress: 4A00   ClockFrequency: 200.000 MHz   Register Stride: 256 bytes   Instance Stride: 4 bytes Configuration pin-out: IO Connections for P3 Pin#  I/O   Pri. func    Sec. func       Chan      Pin func        Pin Dir  1      0   IOPort       StepGen          0        Dir/Table2      (Out) 14      1   IOPort       StepGen          0        Step/Table1     (Out)  2      2   IOPort       StepGen          1        Dir/Table2      (Out) 15      3   IOPort       StepGen          1        Step/Table1     (Out)  3      4   IOPort       StepGen          2        Dir/Table2      (Out) 16      5   IOPort       StepGen          2        Step/Table1     (Out)  4      6   IOPort       StepGen          3        Dir/Table2      (Out) 17      7   IOPort       StepGen          3        Step/Table1     (Out)  5      8   IOPort       StepGen          4        Dir/Table2      (Out)  6      9   IOPort       StepGen          4        Step/Table1     (Out)  7     10   IOPort       SSerial          0        TXData0         (Out)  8     11   IOPort       SSerial          0        RXData0         (In)  9     12   IOPort       SSerial          0        TXData1         (Out) 10     13   IOPort       SSerial          0        RXData1         (In) 11     14   IOPort       MuxedQCount      0        MuxQ-IDX        (In) 12     15   IOPort       MuxedQCount      0        MuxQ-B          (In) 13     16   IOPort       MuxedQCount      0        MuxQ-A          (In) IO Connections for P2 Pin#  I/O   Pri. func    Sec. func       Chan      Pin func        Pin Dir  1     17   IOPort       BISS             0        Din             (In) 14     18   IOPort       BISS             0        Clk             (Out)  2     19   IOPort       SSerial          0        RXData5         (In) 15     20   IOPort       SSerial          0        TXData5         (Out)  3     21   IOPort       SSerial          0        RXData4         (In) 16     22   IOPort       SSerial          0        TXData4         (Out)  4     23   IOPort       SSerial          0        RXData3         (In) 17     24   IOPort       SSerial          0        TXData3         (Out)  5     25   IOPort       SSerial          0        RXData2         (In)  6     26   IOPort       SSerial          0        TXData2         (Out)  7     27   IOPort       MuxedQCountSel   2        MuxSel0         (Out)  8     28   IOPort       MuxedQCount      1        MuxQ-A          (In)  9     29   IOPort       MuxedQCount      1        MuxQ-B          (In) 10     30   IOPort       MuxedQCount      1        MuxQ-IDX        (In) 11     31   IOPort       MuxedQCount      2        MuxQ-A          (In) 12     32   IOPort       MuxedQCount      2        MuxQ-B          (In) 13     33   IOPort       MuxedQCount      2        MuxQ-IDX        (In)

I have the 7i85 on P2 of the 6i25, I connected the encoder to the SERIAL 4 of the 7i85. The encoder status led shows, that the encoder gets the MA clock, but the data transmission fails. Here is stdout after launching the machine.
Code:
LINUXCNC - 2.8.2 Machine configuration directory is '/home/biomech/linuxcnc/configs/my_LinuxCNC_machine_biss' Machine configuration file is 'my_LinuxCNC_machine.ini' Starting LinuxCNC... Found file(REL): ./my_LinuxCNC_machine.hal Note: Using POSIX realtime hm2: loading Mesa HostMot2 driver version 0.15 hm2_pci: loading Mesa AnyIO HostMot2 driver version 0.7 hm2_pci: discovered 6i25 at 0000:02:00.0 hm2/hm2_6i25.0: Low Level init 0.15 hm2/hm2_6i25.0: Smart Serial Firmware Version 43 hm2/hm2_6i25.0: 34 I/O Pins used: hm2/hm2_6i25.0:     IO Pin 000 (P3-01): IOPort hm2/hm2_6i25.0:     IO Pin 001 (P3-14): IOPort hm2/hm2_6i25.0:     IO Pin 002 (P3-02): IOPort hm2/hm2_6i25.0:     IO Pin 003 (P3-15): IOPort hm2/hm2_6i25.0:     IO Pin 004 (P3-03): IOPort hm2/hm2_6i25.0:     IO Pin 005 (P3-16): IOPort hm2/hm2_6i25.0:     IO Pin 006 (P3-04): IOPort hm2/hm2_6i25.0:     IO Pin 007 (P3-17): IOPort hm2/hm2_6i25.0:     IO Pin 008 (P3-05): IOPort hm2/hm2_6i25.0:     IO Pin 009 (P3-06): IOPort hm2/hm2_6i25.0:     IO Pin 010 (P3-07): IOPort hm2/hm2_6i25.0:     IO Pin 011 (P3-08): IOPort hm2/hm2_6i25.0:     IO Pin 012 (P3-09): IOPort hm2/hm2_6i25.0:     IO Pin 013 (P3-10): IOPort hm2/hm2_6i25.0:     IO Pin 014 (P3-11): IOPort hm2/hm2_6i25.0:     IO Pin 015 (P3-12): IOPort hm2/hm2_6i25.0:     IO Pin 016 (P3-13): IOPort hm2/hm2_6i25.0:     IO Pin 017 (P2-01): BiSS Encoder #0, pin data (Input) hm2/hm2_6i25.0:     IO Pin 018 (P2-14): BiSS Encoder #0, pin clock (Output) hm2/hm2_6i25.0:     IO Pin 019 (P2-02): IOPort hm2/hm2_6i25.0:     IO Pin 020 (P2-15): IOPort hm2/hm2_6i25.0:     IO Pin 021 (P2-03): IOPort hm2/hm2_6i25.0:     IO Pin 022 (P2-16): IOPort hm2/hm2_6i25.0:     IO Pin 023 (P2-04): IOPort hm2/hm2_6i25.0:     IO Pin 024 (P2-17): IOPort hm2/hm2_6i25.0:     IO Pin 025 (P2-05): IOPort hm2/hm2_6i25.0:     IO Pin 026 (P2-06): IOPort hm2/hm2_6i25.0:     IO Pin 027 (P2-07): IOPort hm2/hm2_6i25.0:     IO Pin 028 (P2-08): IOPort hm2/hm2_6i25.0:     IO Pin 029 (P2-09): IOPort hm2/hm2_6i25.0:     IO Pin 030 (P2-10): IOPort hm2/hm2_6i25.0:     IO Pin 031 (P2-11): IOPort hm2/hm2_6i25.0:     IO Pin 032 (P2-12): IOPort hm2/hm2_6i25.0:     IO Pin 033 (P2-13): IOPort hm2/hm2_6i25.0: registered hm2_6i25.0: initialized AnyIO board at 0000:02:00.0 Found file(REL): ./custom.hal hm2/hm2_6i25.0: BISS DDS set to 163 hm2/hm2_6i25.0: BISS Filter set to 63 note: MAXV     max: 1.000 units/sec 60.000 units/min note: LJOG     max: 1.000 units/sec 60.000 units/min note: LJOG default: 0.250 units/sec 15.000 units/min waiting for s.joints<0>, s.kinematics_type<0> waiting for s.joints<0>, s.kinematics_type<0> note: jog_order='XYZ' note: jog_invert=set([]) hm2/hm2_6i25.0: Data transmission not complete on channel hm2_6i25.0.biss.00 read. You  may need to change the timing of the hm2dpll timer. This warning  will not repeat hm2/hm2_6i25.0: Data transmission not complete on channel hm2_6i25.0.biss.00 read. You  may need to change the timing of the hm2dpll timer. This warning  will not repeat

I have the DPLL timer in the HAL file of the machine configured as follows.
Code:
loadrt [KINS]KINEMATICS loadrt [EMCMOT]EMCMOT servo_period_nsec=[EMCMOT]SERVO_PERIOD num_joints=[KINS]JOINTS loadrt hostmot2 loadrt hm2_pci config="num_dplls=1 num_encoders=0 num_pwmgens=0 num_stepgens=0 sserial_port_0=00xxxx biss_chan_0=start%2pencoder%36eerror%1bwarning%1bcrc%6p"  addf motion-command-handler   servo-thread addf motion-controller        servo-thread addf hm2_6i25.0.read          servo-thread addf hm2_6i25.0.write         servo-thread setp hm2_6i25.0.watchdog.timeout_ns         5000000 setp hm2_6i25.0.dpll.01.timer-us -200 setp hm2_6i25.0.biss.00.timer-number 1 #  ---estop signals--- net estop-out     <=  iocontrol.0.user-enable-out net estop-out     =>  iocontrol.0.emc-enable-in

The encoder is an EVOLUTE™ RTLA50-S absolute optical encoder with following data format (46b total, position size is 36b).
 

I think I configured the DPLL timer correctly (biss frequency is 500kHz, data transfer of ~50b), so 200us of the DPLL timer should be more than enough. The dpll.phase-error-us does not exceed +-5us.

I did not touch any other parameters of the DPLL timer, however the default value of dpll.prescale should be 1, but in halmeter dpll.prescale shows value of 16.

Could you please help me, where am I making a mistake?

Vaclav, Czech Republic

 

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4 years 9 months ago #231650 by tommylight
Replied by tommylight on topic 6i25 + 7i85 - BISS-C, hm2dpll timing
Ahoj Vaclav,
Had the same "You may need to change the timing of the hm2dpll timer. This warning will not repeat" lately with a perfectly working machine after changing the PC, changed it again to an old Dell and everything works perfectly.
I did play with timings and stuff, did not help much.
The original PC was a Shuttle, old P4, worked for over 5 years till the power supply failed.
The second PC, the one causing issues was a Dell core2duo mini tower.
The third and currently working again Dell SFF core2duo.
5i25/7i77/7i74/7i70/7i71
So try another PC .
www.youtube.com/@toma.cnc1
www.youtube.com/@toma.3d
www.youtube.com/@tomapc

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4 years 9 months ago #231675 by PCW
Replied by PCW on topic 6i25 + 7i85 - BISS-C, hm2dpll timing
What servo thread rate are you running?

"Data Transmission not complete" means the RX logic was busy
when LInuxCNC attempted to read the data. which may mean
either a timing error or that no start bit was detected.

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4 years 9 months ago #231692 by rumking
Replied by rumking on topic 6i25 + 7i85 - BISS-C, hm2dpll timing
Thank you for the suggestions. I am running 1kHz servo-thread.

I managed to get some data from the encoder. There was a flaw in my wiring and after adjusting the timing, it works, partially, atleast.

Setting the dpll.01.timer-us to -500 (minus 5 hundred microseconds) resolved the hm2/hm2_6i25.0: Data transmission not complete error.

However, now I am facing an issue (I am probably lacking some knowledge) with parsing the received bits. Could you help me with the configuration string of the BiSS channel?

The position of the ecoder is 26b (I initially thought it was 36b, but it is 26b, just to clarify).

I would like to parse all the data sent from the encoder. From what I was able to gather, the configuration of the BiSS channel should be (atleast I got most success with):

biss_chan_0=crc%6fwarning%1berror%1bencoder%26e"

This configuration results in:
- encoder position, which seems to be alright (maybe)
- both the error and warning bits are flipping, which they should not
- CRC with 4 bits flipping (which is what I expected) and 2 bits constantly FALSE

With the original configuration (adjusted to proper encoder position size of 26b)

biss_chan_0=start%2pencoder%36eerror%1bwarning%1bcrc%6p"

I get complete non-sense.

Could you help me with construction of the channel configuration string? Can you help me whether or not should I account for the start and "0" bits?

The start and "0" bits are not the first two (if I put the data in plain array of bits), because they are flipping.

I really appreciate your help.

Vaclav

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4 years 9 months ago - 4 years 9 months ago #231718 by PCW
Replied by PCW on topic 6i25 + 7i85 - BISS-C, hm2dpll timing
The BISS firmware starts acquiring data after the start bit, so the 0 would
be part of the data.

Note that inverted data (swapped data lines) would cause the start bit also to be acquired.
(and this would cause an apparent off by 2 error that your CRC shows)

I would check the first 2 bits to see if they make sense (make a string that captures them to individual bits)

I suspect that you may need to swap both the clock and data pairs (and account for the 0 bit)
Last edit: 4 years 9 months ago by PCW.

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4 years 9 months ago #232243 by rumking
Replied by rumking on topic 6i25 + 7i85 - BISS-C, hm2dpll timing
Hi guys,
I got the Renishaw Evolute absolute BiSS-C optical encoder finally working, datasheet is below, these were the obstacles, maybe it will help someone else.

www.renishaw.com/media/pdf/en/75bdde2f02...88845912c86eba6e.pdf

As PCW suggested, swapping the pairs of lines was needed. I swapped only the DATA line, i.e. connected the 7i85 DATA+ to SLO- and DATA- to SLO+. I did not swap the CLK line, i.e. 7i85 CLK+ is connected to MA+ and CLK- to MA-.

Then, a proper configuration of the BiSS channel was needed. I have the 26b position variant of the encoder. With this configuration, everythig is working:

biss_chan_0=null%1bcrc%6fwarning%1berror%1bencoder%26e

Which means the null bit, 6b CRC, 1b waring, 1b error, 26b position. I configured the BiSS frequency to 2MHz and DPLL timer to 100us, running without issues.

setp hm2_6i25.0.dpll.01.timer-us -100
setp hm2_6i25.0.biss.00.timer-number 1
setp hm2_6i25.0.biss.00.frequency-khz 2000

Maybe one last question I have. Is it possible to check the CRC (natively) directly in HAL? Or do I need to develop some kind of RT component which could handle that?

Thank you once again.

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