Multiple Pandrives moving concurrently

[fml]

Hello,

i have two axes which are equipped each with a Pandrive PD113-60 and need to be driven concurrently. Is this possible over RS485? Very exact time synchronization ist not needed, but most part of the movement has to be at the same time. The movement takes about one second.

Can we just send two move commands on the line and then divide apart the responses? Or is it possible, that the motors mess up their backchannel with two answers at the same time?

Thank you for you help,
Michael

[Olav Kahlbaum (TRINAMIC)]

Normally, one should wait for the reply of the last command before sending the next command (otherwise there will be a RS485 bus contention). But it is possible to disable the reply. This can be done using the global parameter 255: SGP 255, 0, 1 disables the replies for all commands except GAP, GGP and GCO. This way you can send the next motion command right after the first one, without having to wait for the reply.
To re-enable the replies for all commands, send an SGP 255, 0, 0 command. This parameter will not be stored in the EEPROM, so after a power-on reset, all replies all also enabled again.

On modules with CAN bus there is a better way to do this: one can set a second can address that can be the same for all modules that should run concurrently. This way only one command will be needed for all modules. On the newer modules (those with ARM processor), such a function will also be integrated for RS485 in one of the next firmware releases. But on the older, AVR-based modules (like the TMCM-113 also) this cannot be done due to lack of memory. So the only choice with the TMCM-113 is to do it like mentioned above.