YASKAWA SIEMENS CNC Series, Maintenance Manual, Serviceman Handbook

Page: 236 / 373

Drive set-up procedure
14.1.6 External encoder
14-26
5. Calculating offset AA.
AA = Un00D
×
(The number of MP scale pulses per motor rotation / (The number of
motor encoder pulses)) - Un00E
Where,
The number of MP scale pulses per motor rotation: A setting value of MD3210 (Pn20A)
and MD3211 (Pn20B).
The number of motor encoder pulses: The number of pulses in the motor encoder list
(See Table 4.2) / 4
Example: For 17-bit encoder, assign 32768.
6. Setting offset
Set MD3508 (Pn808) and MD3509 (Pn809) to AA calculated in the step 5.
AA may be a negative number. For how to set the values, refer to the following exam-
ples.
Example: How to set MD3508 (Pn808) and MD3509 (Pn809) to 1000
a) Set MD3509
MD3509 = 0
b) Set MD3508
MD3508 = 1000
Example: How to set MD3508 (Pn808) and MD3509 (Pn809) to -1000
a) Convert -1000 to an 8-digit hexadecimal number.
Example: -1000 = FFFFFC18H
b) Separate the hexadecimal number into upper and lower words.
Example: Upper word = FFFFH; Lower word = FC18H
c) Convert the upper word to a decimal number again and assign it to MD3509.
Example: FFFFH = 65535
MD3509 = 65535
d) Convert the lower word to a decimal number again and assign it to MD3508.
Example: FC18H = 64536
MD3508 = 64536
Note: After setting MD3508 and MD3509, carry out NCK reset.
EXAMPLE
EXAMPLE