Network Detection Signal - Hitachi SJ200 Series Instruction Manual

4–48
Using Intelligent Output Terminals

Network Detection Signal

The Network Detection Signal output indicates the general status of network communi-
cations. The inverter has a programmable watchdog timer to monitor network activity.
Parameter C077 sets the time-out period. If communications stop or pause longer than
the specified time-out period, the Ndc output turns ON.
Option Terminal
Code Symbol
08 NDc
Valid for outputs:
Required settings:
Notes:
•
To disable the communications watchdog timer, set
C077=00.00 sec.
•
If you set Communications Error Select to
"Disable" (C076=02), you still have the option of
using the Network Detection Signal and setting the
watchdog time-out period with C077.
Additionally, the inverter can respond to a communications time-out in various ways.
Refer to the following diagram (top of next page). You configure the desired response
via function C076, Communications Error Select. This selects whether or not you want
the inverter to trip (alarm with error code E60) and whether to stop the motor or just let it
coast. Together, parameters C076 and C077 set the network detection watchdog time-out
and the inverter's response.
Output
Function Name
State
Network Detection ON
Signal
OFF
11, 12, AL0 – AL2
C076, C077
Description
when the communications watchdog timer
(period specified by C077) has timed out
when the communications watchdog timer is
satisfied by regular communications activity
Example (requires output configuration—
see page 3–46):
Inverter output
terminal circuit
H O OI L
Example for terminals [AL0], [AL1], [AL2]
(requires output configuration—
4–35
see pages and 3–46):
Inverter logic
circuit board
AL0
Power
See I/O specs
supply
on page 4–6.
NDc
FM CM2 12 11
+
RY
–
NDc
AL1 AL2
Load