13
INM 7700 Rev 12
Input
Output Line Fault
Open circuit Open
Closed
Short circuit
Closed Closed
620Ω
Closed Open
10KΩ
Open Open
8 .3 .3 .2
Testing MTL7742 Barriers
The MTL7742 is a single channel switch/prox input barrier with an
open collector solid state interface to the safe area equipment. To
verify correct operation proceed as follows:
a) Connect the barrier as shown in figure 27.
b) Check that the LED is on when the input switch is closed, and
off when the input switch is open.
8 .3 .3 .3
Testing MTL7743 Barriers
The MTL7743 is a dual channel switch/prox input barrier, each
channel with a relay interface to the safe area equipment. To verify
correct operation proceed as follows:
a) Connect the barrier as shown in figure 28.
b) With an ohmeter, check that the output contacts (terminal 1 &
2) close when the input switch for channel 1 is closed.
c) Repeat the procedure for channel 2.
8 .3 .3 .4
Testing MTL7744 Barriers
A dual channel version of the MTL7742, this module provides
two solid state interfaces for prox/switch inputs. To verify correct
operation proceed as follows:
a) Connect the barrier as shown in figure 29.
b) Connect power via the power bus
c) Check that the LED is on when the input switch is closed for
channel 1, and off when the input switch is open for channel 1.
d) Repeat the procedure for channel 2.
8 .3 .3 .5
Testing MTL7745 Barriers
This module is a single channel interface for prox/switch inputs
with line fault detection. To verify correct operation proceed as
follows:
a) Connect the barrier as shown in figure 30.
b) With an ohmeter, check the status of the output contacts
according to Table 3
3
4
1
2
MTL7742
5
6
7
8
}
Ω
Figure 27:
Test circuit for MTL7742
3
4
1
2
5
6
620
10k
24V
Bussed Power
Line Fault
Output
Vs+
Vs
Figure 30:
Test circuit for MTL7745
Table 3
Test conditions for MTL7745
Figure 28:
Test circuit for MTL7743
Figure 29:
Test circuit for MTL7744
8 .3 .3
Tests for MTL774x
The MTL774x range are switch/prox input barriers with a choice of
changeover relay contacts or a solid state switch acting as the safe
area interface. Relay contacts provide a universal interface capable
of switching a wide range of signals including ac, low level and
high level voltages. Phase reversal is achieved by connecting the
normally open or normally closed contacts as required. The solid
state switch variants can be configured to switch from a power
rail or down to ground and makes these barriers ideal for high
switching frequency applications.
When testing bus powered barriers use either an MTL7798 Power
Feed module or an MTL7799 dummy barrier for direct ‘feed-
through’ connection of a 24V dc supply.
8 .3 .3 .1
Testing MTL7741 Barriers
The MTL7741 is a single channel switch/prox input barrier with
changeover relay contacts acting as the safe area interface. To
verify correct operation proceed as follows:
a) Connect the barrier as shown in figure 26.
b) With an ohmeter, check that the output contacts (terminal 5 &
6) close when the input switch is closed.
Figure 26:
Test circuit for MTL7741
