Using A Speed Encoder - Siemens Sinamics G120 CU240E Operating Instructions Manual

5.7.2.4

Using a speed encoder

Higher accuracy by using a speed encoder
A speed encoder increases the accuracy of the speed or the torque of the vector control for
speeds below approx. 10% of the rated motor frequency.
Commissioning the speed encoder
A speed encoder requires the following commissioning steps:
1. Connect the speed encoder (refer below)
2. Set the encoder voltage using the DIP switches on the CU (refer below)
3. Set the speed encoder parameters (refer below)
4. Set the frequency inverter to V/f control (P1300 = 0)
5. Power-up the motor with an average speed
6. Compare parameters r0061 (speed encoder signal in Hz) and r0021 (calculated speed in
7. If the signs do not match, invert the speed encoder signal (P0410 = 1)
8. If the absolute value of the two values do not correspond, check P0408, the speed
9. Change over to vector control with speed encoder (P1300 = 21 or P1300 = 23)
Connect the speed encoder
An encoder can only be connected to CU240S, CU240S DP, CU240S DP-F, CU240S PN or
CU240S PN-F.
Only encoders with two pulse tracks A and B offset through 90° may be connected.
Table 5- 26
Terminal Designation
28
33
70
71
72
73
74
75
Frequency inverter
Operating Instructions, 08.10. 2008, t.b.d.
Hz) regarding the sign and absolute value
encoder wiring and the setting of the corresponding DIP switch
Terminals on the CU to connect the speed encoder
Function
U0V OUT Reference potential of the power supply voltage (terminal 9)
ENC+ Encoder power supply (5 V or 24 V set via DIP switch, max. 300 mA,
SUPPLY CU240S PN-F max. 200 mA)
ENC AP Pulse track A, non-inverting input
ENC AN Pulse track A, inverting input
ENC BP Pulse track B, non-inverting input
ENC BN Pulse track B, inverting input
ENC ZP Zero signal, non-inverting input
ENC ZN Zero signal, inverting input
Functions
5.7 Closed-loop control
115