Hitachi Sj7002 Owners Manual

Using Intelligent Input Terminals
Operations
and Monitoring
4–40
Zero-Return 
Functions   A  zero-return  operation (also called a  home-return) occurs when the motor moves the load to a 
particular starting position. Us ing parameter P068, you may select one of three possible types 
of zero-return operations. Parameter P 069 selects the search direction. The zero pulse input 
(also called  zone input) signals the arrival at the zero position.
It is generally a requirement (or good practice)  to perform...

SJ7002 Inverter
Operations
and Monitoring
4–41
High-speed 2 Zero Return:
1. Motor accelerates for specified 
acceleration time to high zero-
return speed
2. Motor runs at high zero-return 
speed
3. Motor starts deceleration when 
[ORL] signal turns ON
4. Motor runs in reverse direction at 
low-speed zero-return speed
5. Motor starts deceleration to stop 
when [ORL] signal turns OFF
6. Motor accelerates in forward 
direction to low-speed zero return level
7. Inverter stops motor and sets  position value...

Using Intelligent Input Terminals
Operations
and Monitoring
4–42
Pulse Counter 
Signals   The intelligent pulse counter input [PCNT] allows  you to input a pulse train up to 100 Hz via an 
intelligent input terminal. (For  high-speed applications, use the encoder input expansion card 
instead.) Monitor the cumulative count with D028, pulse counter function. The value of the 
cumulative count cannot be stored in a separate  register or parameter. The counter value is 
cleared to zero when inverter power...

SJ7002 Inverter
Operations
and Monitoring
4–43
Using Intelligent Output Terminals
The intelligent output terminals are programmable in a similar way to the intelligent input 
terminals. The inverter has several output functions that you can assign individually to five 
physical logic outputs. Along with these solid-state outputs, the alarm  relay output has type 
Form C (normally open and normall y closed) contacts. The relay is assigned the alarm function 
by default, but you can assign it to any of th...

Using Intelligent Output Terminals
Operations
and Monitoring
4–44
Run Signal   When the [RUN] signal is selected as an 
intelligent output terminal, the inverter 
outputs a signal on that terminal when it is 
in Run Mode. The output logic is active 
low, and is the open collector type (switch 
to common).
The timing diagram to the right shows the 
Run Signal operation in  detail. The inverter 
outputs the [RUN] signal whenever the 
inverter output exceeds the start frequency 
specified by parameter B082...

SJ7002 Inverter
Operations
and Monitoring
4–45
Frequency arrival output [FA1] uses the 
standard output frequency (parameter F001) 
as the threshold for switching. In the figure 
to the right, the inverter accelerates to the 
set output frequency, wh ich serves as the 
threshold for [FA1]. Parameters F
on and Foff 
illustrate the hysteresis  that prevents output 
chatter near the threshold value.

on is 1% of the max. output frequency

off is 2% of the max. output frequency
The hysteresis effect causes...

Using Intelligent Output Terminals
Operations
and Monitoring
4–46
Overload 
Advance Notice 
Signal   When the output current exceeds a 
preset value, the [OL] or [OL2] 
terminal signal turns ON. Parameter 
C041 sets the overload threshold for 
[OL]; parameter C111 sets it for 
[OL2]. The overload detection circuit 
operates during powered motor opera-
tion and during regenerative braking. 
The output circuits  use open-collector 
transistors, and are active low.
Note the following:
 The default threshold...

SJ7002 Inverter
Operations
and Monitoring
4–47
Alarm Signal   The inverter Alarm Signal is active  when a fault 
has occurred and it is in the Trip Mode (refer to the 
diagram at right). When  the fault is cleared the 
Alarm Signal becomes inactive.
We must make a distinction between the Alarm 
Signal  AL and the alarm relay  contacts [AL0], 
[AL1] and [AL2]. The signal AL is a logic 
function, which you can assign to the open collec-
tor output terminals [11]  to [15], or the relay 
outputs. The most...

Using Intelligent Output Terminals
Operations
and Monitoring
4–48
Over-torque 
Signal   The Over-torque function [OTQ] turns ON when th e estimated value of output torque of motor 
increases more than the arbitrary level set for the output (see table below). Recall that the 
torque limit function, covered in  “
Torque Limit” on page 4–30, actually limits the torque 
during certain operating conditions. Instead, the over-torque output feature only monitors the 
torque, turning ON output [OTQ] if the...

SJ7002 Inverter
Operations
and Monitoring
4–49
Use the parameters listed in the table belo w to define Instantaneous Power Failure and 
Under-voltage Signal operation.
In the following examples, t
0= instantaneous power failure time, t1 = allowable under-voltage / 
power failure time (B002), and t
2= retry wait time (B003).
CodeFunctionData or RangeDescription
B001 Selection of  automatic restart 
mode 00 Alarm output after trip, automatic 
restart disabled
01 Restart at 0 Hz
02 Retry with frequency...