Absolute Encoder Questions / SSI via 5i25

PCW wrote:

I can compile a 7I77 bit file some time next week

The raw interface is probably OK for the XMIT side but questionable
on receive because of common mode range. I would always want a real RS-422 driver/receiver there just for ruggedness however

Well, it would be no big thing to make a small PCB with some differential receivers on it. Or simply use a MAX491(EDITED - up to 2.5MBit) and only 2 lines from the 5i25?
@1.5MHz there is no need for advanced layouts, some basic rule obeyment should work. Only for testing of course...

Is it possible to get the Interface on the second port of the 5i25?

Thank you!

best regards,
julian

andypugh wrote:

juwi wrote:

[Is it possible to get the Interface on the second port of the 5i25?

That is what the 7i74 would do. It is a 25-pin D-sub to 8xRJ45 RS422 interface.
(It costs $69)

And takes 4-6 Weeks till I have it
Therefore I'd like to test with what I have till it arrives.

@PCW: It would be very nice from you to get a firmware for 7i77 to start the driver implementation

best regards,
Julian

@PCW: will this cable work?

www.ebay.de/itm/JTAG-Programmer-Kabel-fu...&_uhb=1#ht_738wt_689

Best regards,
Julian

Should, you may need to fuss with the JTAG cable pinout

I know me, once started...

julian

@Andy: I think I must add a SSI struct to hostmot2.h?

Best regards,
Julian

Here is a 5i25 config with 8 SSI interfaces on P2: (7I74 pinout)

freeby.mesanet.com/5i25_ssi.zip

Suggested SSI parameters: (in addition to the normal scaling parameters)

Bitlength (u32)

Clockrate (float)

GrayCode (bit) binary if false, graycode if true

Mask (u32) (some SSI devices have aux data in the stream you need to mask out)
in addition to the always masked MSB --> bitlength-1 in the data register

If you want me to make a config with the free SSERIAL port on a 7I77 used for SSI just ask