Omron DRT2 SERIES DEVICENET SLAVES - OPERATION MANUAL 04-2008 Operation Manual page 96

Functions of General-purpose Slaves and Environment-resistive Slaves
I/O Indicator Status when Short-circuit is Detected (Environment-resistive Terminal Input Units)
SHT0 Indicator Status when Short-circuit Is Detected (Sensor Connector Terminal Input Units and I/O
Units)
I/O Indicator Status when Short-circuit is Detected (Screw-less Clamp Terminal Input Units, Mixed
Units)
power output to the connector where the short-circuit was detected will turn
ON.
Environment-resistive Terminal, Sensor Connector
Terminal, or Screw-less Clamp Terminal
Short-
circuit
Sensor
Note Use a Power Supply Unit with a rated power supply of 50 W for the communi-
cations power supply. A short-circuit is detected when the Unit's sensor power
output current reaches or exceeds 100 mA per input connector. When a short-
circuit occurs, the communications power supply may be temporarily inter-
rupted. After a short-circuit has been detected, the power will be automatically
restored, but during the power interruption use an external circuit in the con-
figuration to make sure the system is operating safely.
Use the following equations to calculate the sensor's current consumption.
Total network current = Total Unit current consumption + Total sensor current
consumption
Communications power supply capacity ≥ (Total network current + Short-cir-
cuit detection current) x (=100 mA) x (DeviceNet network voltage)
-A
The box indicates the number of the corresponding connector.
Note 1. Refer to SECTION 6 Environment-resistive Slaves for the position of the
actual indicator.
2. After a sensor short-circuit is detected, a delay of up to 1.2 s will occur be-
fore the Sensor Power Shorted Flag is turned ON.
This indicator lights red when a short-circuit error is detected.
This indicator lights red when a short-circuit error is detected.
0 to 15
Lit red.
Has the sensor power
shorted?
-B
Section 4-3
75