Short-Circuit Detection Function - Mitsubishi Electric NZ2GF12A4-16D User Manual

8.9

Short-Circuit Detection Function

This function detects a short circuit in each of input ports and output channels.
Short-circuit detection on each input port
A short circuit of the sensor power supply is detected in each of input ports.
■Operation overview
A short circuit is detected when the sensor power supply current exceeds the judgment value. Since a supply current is
shared with two sensor power supplies in a port, a short-circuit in either one or both of the two sensor power supplies is
detected. The current flowing through the sensor power supply of the port where a short circuit has been detected stops.
■Judgment value for short-circuit detection
A supply current to a set of two sensor power supplies (total current of the two sensor power supplies) is 400mA or more.
■Notification of a detected short-circuit
When a short circuit is detected in a set of two sensor power supplies, the following operation is performed.
• The LEDs of the two sensor power supplies in the port turn on in red.
• The corresponding bit of Input X port status (RWr4)
Ex.
When a short circuit is detected in the port for X0 and X1 inputs of the NZ2GF12A4-16D with a 4-wire sensor connected
4-wire sensor
Detection circuit
Pin number
(1)
(2)
(3)
(4)
(5)
For example, when a short circuit is detected in X0, both the X0 LED and X1 LED turn on in red because X0 and X1 share the
same port. The bit 0 (PS0) of Input X port status (RWr4) turns on.
■When a short circuit is eliminated
After a short circuit in a set of two sensor power supplies is eliminated and the two sensor power supplies in the port return to
their normal conditions, the following operation will be performed.
• The LEDs of the two sensor power supplies in the port turn on in green.
• The corresponding bit of Input X port status (RWr4)
*1 For details, refer to the following.
Page 149 Input X port status
*1
turns on.
NZ2GF12A4-16D(X0, X1 input port)
(1)
(4)
Checking for
short circuits
Signal name
+24V (UNIT)
X1
24G (UNIT)
X0
FG
*1
turns off.
(2)
(3)
(5)
8 FUNCTIONS
8.9 Short-Circuit Detection Function
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