Cool Components: ACS EtherCAT To Analog Drives
One complaint I have about most proprietary motion control field buses is that the I/O choices available are very limited.Â Standard field buses such as CANOpen, Ethernet PowerLink, and EtherCAT have a much better selection of I/O modules as well as a wide selection of drives, but there’s one device that’s hard to find on most motion networks, proprietary as well as standard: an interface to analog servo drives.
Analog servo amps are still important because specialized equipment such as piezo motors can require you to use a custom servo amplifier, which typically has a +/- 10V analog input.Â So if you want to use these devices on a network, you’re out of luck — unless you can get a network to analog drive.
The Logosol LDCN is the only proprietary motion network I know of that has drives with an analog output (they are the LS-160, LS-170F, and LS-180).
I’ve only found one company making analog output drives for a standard motion network: the ACS Motion EtherCAT intefaces.Â ACS has various models.Â The SPiiPlusUDI modules can control 2 or 4 analog servo amps.Â The SPiiPlusPDM modules can control 2 or 4 step/dir input drives, including step/dir servo drives, stepper drives, or laser generators.
I think the UDI modules are more useful, but I’m sure the PDM modules can be handy.Â For example, if you want to use a proprietary Asian servo motor that has to be used with a proprietary drive that takes step/dir input.
Important note: after I wrote this, I had a discussion with a local ACS distributor, and he said he was pretty sure that the ACS EtherCAT drives and modulesÂ will only work with ACS motion controllers (hardware or software).Â So, if you’re interested in these modulesÂ but don’t want to go 100% ACS, please check first.