Diagnostic And Test Features; Individual Sector Indicators (Isi); External Device Monitoring (Edm); Machine Test Signal (Mts) - Omron MS2800E Operation Manual

6-1

Individual Sector Indicators (ISI)

6-2

External Device Monitoring (EDM)

6-3

Machine test signal (MTS)

6-4

Range selection

All MS2800 systems have two visible, red LEDs on the receiver
close to the lowest and the uppermost beam for easy alignment
of the devices. Every LED represents one half of the protected
area. If one optical beam in one half is interrupted, the referring
LED will light. When synchronization fails, both LEDs will light.
Additionally, error codes are displayed using a set of red LEDs
close to the connector endcap. The Individual Sector Indicators
are not a safety critical component. A failure of the ISI will not
cause an alarm condition and the system will continue to oper-
ate.
EDM is an important safety function. It monitors the MS2800 system interface
to the guarded machine, checks to ensure that the control elements are
responding correctly to the light curtain and detects any inconsistency
between the two external control devices. This is necessary to detect a mal-
function within the interface which prevents a stop signal from reaching the
machine controller. The connection for the EDM is made at the receiver. On
power-up, the MS2800 system looks for a closed to 0 VDC condition. If this is
found, it will enter a state consistent with the selected operating mode. When
the MS2800 system enables its safety outputs, it monitors the external
devices for a closed to open transition. This transition must occur within
300 ms or the MS2800 system will then enter an alarm state. Additionally, if
the EDM connections are incorrectly wired, the system will enter an alarm
state.
Note For proper operation of the MS2800 system when EDM is not active, the EDM
input must be wired to the MS2800 system 0 VDC line.
The EDM function can be activated and deactivated using the selector
switches on the receiver unit.
Some applications require that the machine guarding system be tested by the
machine controller during a non-hazardous portion of the machine cycle to
verify that the guarding system is functioning properly. The MTS option on the
transmitter provides this capability. The MTS is provided by placing a nor-
mally-closed switch across the MTS and MTS Return lines of the transmitter.
When the transmitter recognizes a close-to-open transition on this switch a
beam block state will be simulated on the transmitter and the receiver will
enter the MACHINE STOP state. MTS is active as long as the switch is held
open.
The MS2800 offers operating range selection: short range is 3 m and long
range is 7 m for the 14 mm models. For the 30mm models the short range is
8 m and long range is 20 m. This function is useful when there are many light

Diagnostic and Test Features

SECTION 6
17