Omron MS4800E, Руководство по эксплуатации

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17
SECTION 6
Diagnostic and Test Features
6-1 Individual Beam Indicators (IBI)
All MS4800 systems have a visible red LED as an Individual Beam Indicator
adjacent to each infrared beam. These IBIs are located on the receiver. The
IBI will light when the infrared beam fails to meet the conditions necessary for
the system to remain in the MACHINE RUN state. When less than 10 consec-
utive beams are clear, every other IBI will light indicating that the MS4800 is
not synchronized. IBIs are not a safety critical component. An IBI failure will
not cause an alarm condition and the system will continue to operate.
Additionally, error codes are displayed using the IBIs close to the connector
endcap.
6-2 External Device Monitoring (EDM)
EDM is an important safety function. It monitors the MS4800 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 MS4800 system looks for a closed to 0VDC condition. If this is
found, it will enter a state consistent with the selected operating mode. When
the MS4800 system enables its safety outputs, it monitors the external
devices for a closed to open transition. This transition must occur within
300ms or the MS4800 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 MS4800 system when EDM is not active, the EDM
input must be wired to the MS4800 system 0 VDC line.
The EDM function can be activated and deactivated using the selector
switches on the receiver unit.
6-3 Machine test signal (MTS)
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.
6-4 Range selection
The MS4800 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
8m and long range is 20 m. This function is useful when there are many light
curtains operating within a small space and the possibility of cross-talk is
likely.