Acs800880 Master Follower Guide
Acs800880 Master Follower Guide
Acs800880 Master Follower Guide
Description:
The ACS880 can be used to replace an ACS800 in an existing master follower application
without modifying any ACS800 parameters or wiring. As long as the ACS880 is configured
properly it can replace an ACS800 as the master or the follower. The ACS880 can read and
pass data through the fiber link exactly like the ACS800 can. This makes it easy to transition
existing ACS800 customers over to the ACS880, and gives users more options for current
master follower applications containing ACS800 drives. This document contains information to
help install an ACS880 in a master follower application with existing ACS800 drives.
The M/F link for the 880 is a two fiber wire connection just like the 800. The 880 can be
programmed to pass and read data like an 800, so the fiber wire configuration is the same.
ACS880 drives with a ZCU control unit require a FDCO DDCS communication module.
ACS880 drives with a BCU control unit require an RDCO module. The figure below illustrates
how the fiber link is made for both control units as followers.
This section contains the parameter configuration for ACS800 and ACS880 drives as masters,
followers in torque mode, and followers in speed mode.
The tables below shows the typical parameter settings for an ACS800 drive setup as a master.
The ACS880 parameters listed show how to configure an 880 to replace an 800 master. These
are only the parameters related to the M/F link. The motor data, start/stop, speed control, and
other parameters need to be configured as well, but are not within the scope of this document.
Because these followers are in torque mode the speed window can be adjusted in both drives.
The window control for the 800 is also in the 880 and is configured the same way, but the
parameter names and numbers are different. The table below shows the 800 window control
parameters and the corresponding 880 parameters.
Other parameters to consider are the min and max speed settings of the followers. The
absolute value of the min/max speed must be greater than the value set in the master in order
for the followers to share load equally at max/min speed. If the max speed values for the
followers are not greater than the master the load will not be shared equally at max speed. This
occurs even though the followers are in torque mode because the speed regulator works to
ensure the maximum speed value is not surpassed, and it will limit the torque output of the
follower as the actual speed gets closer to the maximum speed.
The following tables show how to configure an ACS800 as a speed follower and an ACS880 the
same way. An 800 and 880 with these settings can work together as followers in the same
application.
Other parameters to consider are the min/max speed settings of the followers. Ensure the
absolute value of the min/max speed parameters are greater than that of the master. This is to
keep the speed regulator from limiting the followers torque while running at the master’s min or
max speed. Also, the ACS800 and ACS880 have a droop rate parameter which will allow for a
slight speed difference between the master and follower drives. The droop rate is parameter
60.06 in the ACS800, and 25.08 in the ACS880.