Need Help!- sevostar cd rdc error

[PBr]

Hi,

I am trying to get work a servostar CR06250 drive with an standard ac servomotor with resolver feedback. I've come to a problem with the feedback device (which is a 2 pole resolver), the problem is, that after speeding up the motor to 2000rpm, the drive stops and a fault message apeears on the display saying RDC error.
Also the resolution of feedback is set to 14 bits by drive, but when i rotate the shaft manually, the position is always incremented by 256 units, which gives only 256 counts per revolution. The shaft position counter counts from 0 to 65535.
I suspect that this resolution problem is related to my main problem.
The cables to motor are shielded and about 0.5m long, so that doesn't affect the drive.

Any suggestions?

[mike_Kilroy]

r2 error says r/d converter has a problem right.... did this drive work once and just now break? unknown condition? hmmm... rdc error is not common.....

I would give it a labotomy and start over - type clreeprom to reset all variables to factory defaults and see if that helps....

U shud be able to get to 6100rpm with RDRES=112 bit, somewhere less at 14bit and 1500rpm max at 16 bit......why do u want 14bit setting? 99.9% of apps can use 12bit.

PRD is indeed 0-65535 range per rev on all drives, PFB counts up to like 32bit word b4 rolling over, not sure what variable u are seeing as 0-256.... If PFB (position feedback) is 0-256 and rolls over then perhaps you have the rollover variable turned on and set to 256 - again, unless u need this, turn it off or do clreeprom and start fresh. i'd tell u the variable but it is late and i cant remember right now

let us know if we can help more?

[PBr]

Originally Posted by mike_Kilroy r2 error says r/d converter has a problem right.... did this drive work once and just now break? unknown condition? hmmm... rdc error is not common..... I would give it a labotomy and start over - type clreeprom to reset all variables to factory defaults and see if that helps.... U shud be able to get to 6100rpm with RDRES=112 bit, somewhere less at 14bit and 1500rpm max at 16 bit......why do u want 14bit setting? 99.9% of apps can use 12bit. PRD is indeed 0-65535 range per rev on all drives, PFB counts up to like 32bit word b4 rolling over, not sure what variable u are seeing as 0-256.... If PFB (position feedback) is 0-256 and rolls over then perhaps you have the rollover variable turned on and set to 256 - again, unless u need this, turn it off or do clreeprom and start fresh. i'd tell u the variable but it is late and i cant remember right now let us know if we can help more?

Hello,

thanks for your reply.
The drive i bought on ebay, so condition is unknown Ill try reset the eeprom.

Regarding to your remarks about resolution, the fact is, that the bit count (12,14,16) depends on max. motor speed, so i can't set it directly.

I'm sorry, but i didn't express myself clearly about the PRD range. The problem is, that in my drive is it in range of 0-65535, but it changes only in increments of 256. So PRD is like 0, 256, 512, 768, 1024 etc. Nothing between those values, no matter how gently i rotate the shaft.

Today a tested the motor with an other drive (CR03260) and it worked just fine after he first powerup. The PRD worked fine also. So the result is unambiguous, the drive has some kind of error. I think it can be caused by some passive component in the RDC part. I'll check it when i'll have some time and a scope available.
Or any other ideas what can be wrong?

[mike_Kilroy]

RDRES is read/write - YOU decide what to set it to. so yes, you can set it. just type RDRES 12 in terminal window or type CLREEPROM to reset it to 12 bit, the default.

clreeprom shud fix u up. if not perhaps u r right and components are broke. we rpr these and if it needs new control card it prob would cost around $ 1000 if u r interested.

cant say why PRD shud count in 256 increment steps.... never saw that in 20 years of intense daily working with this drive.

[PBr]

So today i quickly tried your suggestions, but unfortunately without success.
I tried also to set the RDRES variable, but it cannot be written.

I forgot to check the firmware version, maybe a upgrade will fix it.

Also after disassembling the drive i saw, that the RDC converter is made of RDC19222 chip, which might be bad.

[mike_Kilroy]

OOPS; sorry. too many drive types to keep all read/write variables in mind. You are correct on that drive - read only. BUT YOU do set it - by setting VLIM variable (set directly in terminal window or on velocity limits page - hover mouse over bottom left fields on page to see which is overspeed and which is VLIM. Just set it to 7000rpm for now to force RDRES = 12 to try it.

Here is help descrip FYI:

RDRES

displays the resolver resolution on resolver-based systems. RDRES is a read-only variable which is automatically calculated in order to achieve maximum resolution. The setting is based on VLIM, which is the maximum application velocity. The relationship between VLIM and RDRES is given below:
if (VLIM ³ 6101) then RDRES = 12
if (1501 £ VLIM £ 6100) then RDRES = 14
if (VLIM £ 1500) then RDRES = 16

Firmware Versions: all
Type: switch mode (R) Range: 12, 14, or 16
Units: bits Default: n/a
Opmodes: all Drive Status: en/dis EEPROM: no

[PBr]

Hello,

so i tested everything i could, upgraded the firmware. The results were same.
I studied the datasheet for RDC, it has 16 bit outputs (2 bytes), ie range from 0-65535. It has also 2 inputs, which enable the low and high byte latch. Maybe the low byte enable input isn't driven low (active) to enable the outputs, therefore the position is incremented exactly by 256. I don't have a scope to check it now. But it is a too complicated PCB for repair it without schematics.

[mike_Kilroy]

checking to see if bosses will allow us to offer you replacement control card for cheap to get u running.. in meantime, if u want, tell us how much a new card wud be worth to u?

[PBr]

OK, thank you.
Let's discuss the details in private.

[MKC]

Good morning! We do replace the control cards and retest these drives on a regular basis however the price below was misquoted so please disregard. Private message sent.