Omron DRT2 Series Operation Manual page 21

DRT2 Features
Operation Time Monitor
Environment-resistive Terminal Features
Dust-proof and
Waterproof Construction
(IP67) for High Resistance
to Environment
No Power Supply Wiring
for Input Devices
Connect High-load
Devices (1.5 A Max.)
Detection of Sensor Power
Short-circuit
External Load Short-
circuit Detection
(Environment-resistive
Terminal Output Units
Only)
Sensor Disconnected
Detection
Analog Slave Features
Setting the Number of AD
Conversion Points (Input
Units Only)
Moving Average (Input
Units Only)
Scaling
4
The time that lapses from when the output turns ON to when the input turns
ON can be measured at high speed from the Slave (without relying on the lad-
der program). The Slave also maintains a set value for monitoring the opera-
tion time, and will provide notification the Status Area if the set time is
exceeded. The Configurator or explicit messages can be used to read the
information.
Note The Operation Time Monitor can be used only with Slaves that consist of a
Basic Unit and an Expansion Unit and also provide both inputs and outputs.
The environment-resistive construction enables usage in locations subject to
oil and water splashes (IP67). An environment-resistive box is not required,
enabling greater downsizing and reducing wiring labor.
Power for communications, internal circuits, and input devices is shared, mak-
ing wiring necessary only for the communications power supply.
The rated output current is 1.5 A, allowing the direct connection of output
devices with high loads.
The I/O power and current are monitored and if the current exceeds 100 mA
at the connector, it is regarded as a sensor power short-circuit and the sensor
power output is forced OFF. The number of the shorted contact can be
checked from the I/O status indicators. The Configurator or explicit message
communications can also be used to read which connector or sensor has
shorted. The Slave will automatically reset when the cause of the short-circuit
has been removed.
External Load Short-circuit Detection monitors the load current of Output
Units, and if the Output Unit's current exceeds the rated 1.5 A, it is regarded
as an external load short-circuit and the output is forced OFF to prevent dam-
age to the Unit's output circuit. The Configurator or explicit message commu-
nications can used to read which output load has short-circuited. The method
of canceling short-circuit protection can be set to an automatic or manual
reset using the Configurator or explicit messages. (The default setting is for a
manual reset.)
The I/O power and current are monitored and if the current drops below
0.5 mA at the connector, it is assumed that the sensor is disconnected. The
Configurator or explicit messages can be used to read which sensor is not
connected.
The conversion cycle when all 4 analog input points are used is 4 ms max.
The AD conversion cycle can be shortened by reducing the number of points
used (i.e., the number of AD conversion points).
Analog Input Terminals can calculate the average of the past eight analog
input values to produce a stable input value even when the input value is
unsteady.
Scaling allows values to be converted according to the industry unit required
by the user. It reduces the number of operations requiring ladder program-
ming in the Master CPU Unit. Scaling also supports an offset function for com-
pensating for errors in scaled values.
Section 1-1