ABB ACS880 - Example 3: ACS 600; ACS800 Compatibility

The line speed measured by encoder 2 can be read from 90.3. This value is given in
rpm which can be converted into another unit by using 90.53 and 90.54. Note that the
feed constant gear cannot be used in this conversion because it does not affect 90.3.
Example 3: ACS 600 / ACS800 compatibility
With ACS 600 and ACS800 drives, both the rising and falling edges from encoder
channels A and B are typically counted to achieve best possible accuracy. Thus the
received pulse number per revolution equals four times the nominal pulse number of
the encoder.
In this example, an HTL-type 2048-pulse encoder is fitted directly on the motor shaft.
The desired initial position to correspond the proximity switch is 66770.
In the ACS880, the following settings are made:
•
92.1 = HTL
•
92.2 = Module 1
•
92.10 = 2048
•
92.13 = Enable
•
90.51 = Encoder 1
•
90.63 = 8192 (ie. 4 × value of 92.10, as the received number of pulses is 4 times
nominal. See also parameter 92.12)
•
The desired “data out” parameter is set to Other – 90.58 (32-bit format). Only the
high word needs to be specified – the subsequent data word is reserved for the low
word automatically.
• The desired sources (such as digital inputs or user bits of the control word) are
selected in 90.67 and 90.69.
In the PLC, if the initial value is set in 32-bit format using low and high words
(corresponding to ACS800 parameters POS COUNT INIT LO and POS COUNT INIT
HI), enter the value 66770 into these words as follows:
• Eg. PROFIBUS:
• FBA data out x = POS COUNT INIT HI = 1 (as bit 16 equals 65536)
• FBA data out (x + 1) = POS COUNT INIT LO = 1234.
• ABB Automation using DDCS communication, eg.:
• Data set 12.1 = POS COUNT INIT HI
• Data set 12.2 = POS COUNT INIT LO
To test the configuration of the PLC, initialize the position counter with the encoder
connected. The initial value sent from the PLC should immediately be reflected by 90.7
60 Program features