6.3 SEMI F47 Function
6-12
6.3
SEMI F47 Function
The SEMI F47 function detects an A.971 warning (Undervoltage) and limits the output current if
the DC main circuit power supply voltage to the SERVOPACK drops to a specified value or
lower because the power was momentarily interrupted or the main circuit power supply voltage
was temporarily reduced.
This function complies with the SEMI F47 standards for semiconductor manufacturing equip-
ment.
You can combine this function with the momentary power interruption hold time (Pn509) to
allow the Servomotor to continue operating without stopping for an alarm or without recovery
work even if the power supply voltage drops.
Execution Sequence
This function can be executed either with the host controller or with the SERVOPACK. Use
Pn008 = n.
X
(Function Selection for Undervoltage) to specify whether the function is exe-
cuted by the host controller or by the SERVOPACK.
The default setting (Pn008 = n.
0
) disables detection of an A.971 warning (Undervoltage).
Execution with the Host Controller (Pn008 = n.
1
)
The host controller limits the torque in response to an A.971 warning (Undervoltage).
The host controller removes the torque limit after the Undervoltage warning is cleared.
Parameter
Description
When Enabled
Classification
Pn008
n.
0
(default set-
ting)
Do not detect undervoltage.
After restart
Setup
n.
1
Detect undervoltage warning and limit torque
at host controller.
n.
2
Detect undervoltage warning and limit torque
with Pn424 and Pn425 (i.e., only in SERVO-
PACK).
280 V
200 V
0%
0%
Torque limit ends.
The torque is limited when the
Undervoltage warning is received.
Torque limit starts.
The main circuit bus voltage increases when
the main circuit power supply recovers.
The output torque is limited to suppress
the drop in the main circuit bus voltage.
Torque limit
reference
Undervoltage
warning status
Torque control
A.971 warning
(Undervoltage)
Main circuit
bus voltage
Main circuit input
power supply
Host controller
SERVOPACK
Main circuit power interruption time
