[etherlab-users] Adapting 'user' example for FB1111-014x

[Maarten Burghout]

On 15-11-2010 15:52, Thorsten Schnebeck wrote:
> Am Montag, 15. November 2010, um 15:23:15 schrieb Maarten Burghout:
>> Unfortunately, I'm still trying to establish PDO-exchange between
>> my master and a Beckhoff FB1111-014X SPI slave.
>>
>> Main problem seems to be the absence of pdo-entries in the slave
>> configuration. Output of "ethercat cstruct":
>>
> Hi,
>
> just as a side node. You know that you need a µC controlling the
> FB1111-014X SPI slave that runs Beckhoffs slave sample code or your
> own adaption of the ethercat protocol stack? Only the
> 32-BIT-IO-FB1111-0142 type runs without further µC assistance.

Does this also hold when Device Emulation (see notes at AL control 
register 0x0120) is enables, like I did (and didn't mention in my 
earlier message)?

> Our result was that for a low latency control loop with up to 20KHz
> the SPI-slave is too slow. We need too much time to get the ethercat
> frame from the slave controller to the µC (dsPICF, 40Mips). Now we
> check a control system with a stack of FB1111-0142 but I have no
> results so far :-)

At this moment, we are aiming for a 1kHz control loop. Given a PWM value 
represented by a 16-bit word, and an encoder value in 32-bit 
representation, I'd think SPI (running at 5MHz at the moment, could be 
increased to 20MHz if necessary) would be able to handle that.

> HTH
>
> Thorsten

Kind regards and grateful for your answer,

Maarten Burghout