Yaskawa Varispeed 626M5 - Manual (Page 293)

15.4 Interface Design
15 -21
15.4.2 Speed Reference Signals (M5A Stand-alone Drive)
As shown in Fig. 15.22 and Fig. 15.23, the speed reference signals can be used as either analog or digital
signals. Analog signals have a rated speed reference of ±10 V. Voltage drop due to wiring impedance and
drift due to temperature variations and wear and tear can be adjusted using the control parameters in the
Inverter, and the control parameters and adjustment resistors at PLC and NC.
The digital speed references (1CN) uses both BCD and binary signals. In this case, reference errors due
to temperature drift and voltage drop do not occur, unlike with analog signals. Also, if speed variation is
not continuous, the speed setting parameters within the Inverter are switched externally so that multi-step
speed operations can also be used. The digital speed reference (1CN) input circuit is the same as the se-
quence input signal (6CN). The signal circuit common can be selected independently of the sequence input
signals (refer to Fig. 15.21).
For the signal details, refer to 4.2 Analog Speed References (Stand-alone Drive), and 4.3 Using a 12-bit
Digital Speed Reference.
PC, NC Inverter
±10 V
D/A
Fig 15.22 Example of Analog Speed Reference Signals
PC, NC Inverter
Level
conver-
sion
Fig 15.23 Example of Digital Speed Reference Signals
15.4.3 Sequence Output Signals (M5A Stand-alone Drive)
Sequence signals such as zero speed and malfunction signals, which notify externally the Inverter opera-
tion status, use the relay contacts and transistor switches. The transistor switch output circuit is bi-direc-
tional, as shown in Fig. 15.24, so both the 0-V common and +24-V common can be used, in the same way
as for the relay outputs.
Fig 15.24 Output Interface Circuit
15