8I20 14
OPERATION
DRIVE PARAMETER SETUP
BRAKEONV and BRAKEOFFV
BRAKONV and BRAKEOFFV set the brake on and brake off voltage thresholds.
These are used to clamp the rising motor bus voltage created when decelerating. When
decelerating, the 8I20 will charge the motor power supply filter capacitors with regenerated
energy .
The default values (on at 360V off at 340V) are chosen to match a 240V off line
power supply, and to protect the 8I20. If lower power supply voltages are used (with lower
filter capacitor voltage ratings) the BRAKEONV and BRAKEOFFV voltages should be set
lower to protect the power supply. It is suggested that BRAKEOFFV be set 20V lower than
BRAKEON. BRAKEONV and BRAKEOFFV are specified in units of 10mV. That is a
BRAKEONV value of 30000 would specify 300.0 V.
The startup values of BRAKEONV and BRAKEOFFV are set with the parameters
NVBRAKEONV and NVBRAKEOFFV.
For example:
WPD NVBRAKEONV 19000
WPD NVBRAKEOFFV 17000
Would be suitable values for a 120V line operated supply with a maximum rating
of 200V. Note that like all EEPROM parameters, these settings will not take effect until the
8I20 has been reset.
OPERATE MODE BAUD RATE
The operate mode baud rate default is 2.5 MBaud. This should not be changed
unless needed for non-standard applications. Baud rates are selected by writing an index
value to the NVBAUDRATE parameter. The index numbers for available baud rates are
as follows:
INDEX
BAUD
INDEX
BAUD
INDEX
BAUD
0
9600B
1
19200B
2
38400B
3
57600B
4
115200B
5
230400B
6
460800B
7
921600B
8
1.25MB
9
2.5MB*
10
5MB
11
10MB