Hitachi L2002 Manual Do Utilizador

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L200
2
 Inverter
Oper
ations
and Monitor
ing
4–49
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. 
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.
Option 
Code
Terminal 
Symbol
Function Name
Output 
State
Description
08
NDc
Network Detection 
Signal
ON
when the communications watchdog timer 
(period specified by C077) has timed out
OFF
when the communications watchdog timer is 
satisfied by regular communications activity
Valid for outputs:
11, 12, AL0 – AL2
Required settings:
C076, C077
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.
RY
+
Example (requires output configuration—
see page 
):
Inverter output 
terminal circuit
NDc
12 11
CM2
Example for terminals [AL0], [AL1], [AL2] 
(requires output configuration—
see pages 
AL0
AL2
AL1
Inverter logic 
circuit board
See I/O specs 
on page 
NDc
Load
Power
supply