Operating instructions

Function

Leuze electronic MSI-SR4 8

Single-channel E-STOP circuit, manual start

(see figure 3.1)

After applying the supply voltage to A1 and A2 and with the E-STOP button not actuated, relays K1 and

K2 pick up upon actuation of the start button and lock. The release circuits 13-14, 23-24 and 33-34 close,

signal circuit 41-42 opens. Upon actuation of the E-STOP button, K1 and K2 go dead and drop out. The

release circuits open, the signal circuit closes. With one-channel E-STOP wiring, up to category 2 acc. to

EN ISO 13849-1: 2009 is achieved. Earth faults in the button circuit are detected.

Two-channel E-STOP circuit, manual start

(see figure 3.2)

Function/operating principle as described above. In addition, contactor contacts K1 and K2 are looped into

the start circuit (reset) (EDM).

With two-channel E-STOP wiring, up to category 4 acc. to EN ISO 13849-1: 2009 is achieved.

Downstream safety circuit for Optoelectronic Protective Devices type 4, EN 61496-1

(see figure 3.3), (see figure 3.4)

Optionally, Light Beam Safety Devices of type 4 can be connected with relay outputs (see figure 3.3) or

with fail-safe semiconductor outputs (see figure 3.4). When calculating the safety distance, the regression

delay of the MSI-SR4 of 10 ms must be included. As an alternative to the start circuit, a bridge can be

placed between S34 and S35 for automatic start. With this operating mode, it must not be possible to reach

or step behind the Light Beam Safety Device.

Two-channel sliding safety guard monitoring

(see figure 3.5)

Based on the specified signal sequence, when using two, forced position switches, the direction-depen-

dent actuation of the contacts, e.g. of a safety guard, is monitored. For automatic start (bridge S34 - S35),

reaching or stepping behind must not be possible.

Signal sequence monitoring

The function expects the first signal at S22 and the second signal at S12. The time offset is arbitrary. If,

due to, e.g., misalignment of a contact actuator, the times of the signals are swapped, this is tolerated up

to max. 20 ms. Afterwards, the release circuits of the MSI-SR4 close. Signal sequence monitoring is only

active if wired for automatic start. The EDM signal must be applied for max. 20 ms at S12 after the signal

is received.

Monitoring of the S inputs

In the event of a cross connection at inputs S12 and S22 or of a short circuit of input S12 to ground, output

relays K1 and K2 are switched off via an electronic fuse. The MSI-SR4 is again ready for operation approx.

2 s after the cause of the malfunction has been eliminated.

Figure 3.5: Connection example 5

+24V

MSI-SR4

S22

S12

S31

S35

S34

S33

closed

open