MFU-M1:
Controls Information
To
enlarge the diagram click on the controls diagram below.
Status
Indicators
Inputs
- Green LED ON when input is ON
Outputs
- Green LED ON when input is ON
Reset
- Yellow LED ON when reset input is ON
EDM
- Yellow LED ON when EDM inputs are ACTIVE
Status
- RED LED's ON steady when the system is OK
RED LED's flash ON/OFF when the system is in lockout
Wiring
Information
Terminals
A1 and A2 – Power supply input - Connect
a suitably stabilized 24V DC power supply to terminals A1 = +24V DC and A2 = 0V
DC. The current consumption of the
MFU with no load applied on the output switching terminals is 150mA.
Terminals A3 and A4 – External device
monitor (EDM) - Normally closed switch contacts, in series from the external
power switching devices are connected across terminals A3 and A4.
The monitoring circuit checks that the power switching devices both de-energize
at the same time the MFU safety output switches de-energize.
If one or both of the power switching devices fail to de-energize at this
time the MFU goes into a lockout condition, turning all output switches off.
To
reset from a lockout condition it is necessary to remove the 24V DC supply from
the MFU and then re-apply.
If
the EDM circuit is not used it is necessary to link terminals A3 to A4 otherwise
the system will go to a lockout condition at the next demand upon the safety
system.
Terminals A5 and A6 – Safety output 1
switch contact -
Connect terminals A5 and A6 to one channel of a machine’s stop circuitry.
For example, via an external power-switching relay or directly to a safe
PLC input or a machines final control element.
Terminals A7 and A8 – Safety output 2
switch contact -
Connect terminals A7 and A8 to one channel of a machine’s stop circuitry.
For example, via an external power-switching relay or directly to a safe
PLC input or a machines final control element.
If
a single channel safety circuit is used link terminals A6 and A7.
Terminals A5 and A8 are then connected to the machine’s safety circuit.
Connecting in this way links safety output switch 1 and safety output
switch 2 in a series configuration.
Terminal
A9 – No connection
Terminal
A10 – Auxiliary electronic switching output 1 - The Auxiliary switching
output should only be used for non-safety critical application.
For example connecting an indicator lamp or as feedback to a PLC to
confirm the safety outputs have de-energies.
The
auxiliary output energizes when safety output switches 1 and 2 energize and de-energizes
when the safety outputs de-energize. Auxiliary
output ON = 24V DC and OFF = 0V DC.
Terminal A11 – Auxiliary electronic switch
– mute out.- The Auxiliary switching circuit energizes when the light curtain is
muted, e.g. when suitable signals have been applied to terminals B2 and B3.
The output switch is normally used for connecting an indicator lamp or as
feedback to a PLC to confirm safety light curtain inputs at terminals B1 and B2
are overridden e.g. in a muted condition.
Terminal A12 – Reset - A suitable switch should be connected between terminal A12 and
the 24V DC supply. If the safety
output relays de-energize a depression of the switch is required to re-energize
the output switches to an ON condition.
The
MFU’s safety output switches will only re-energize when the reset switch is
depressed and then released.
Terminal
B1 and B2 – light curtain inputs (OSSD1 and OSSD2)
- Connect the
electronic output switches (OSSD1 and OSSD2) of a light curtain to terminals B1
and B2 respectively.
Note:
An internal circuit monitors disparity between the two input channels.
If the inputs do not switch together (within 500ms of each other) the
system will go into a lockout condition.
Important: If terminal B1/B2 are not used it is necessary to link
them to the 24V DC supply. If not
the MFU’s output switches will not energize.
Terminal B3 and B4 –
mute input signals - Connect
suitable mute initiating signals to terminals B3 and B4 respectively.
The mute signals override the light curtains operation therefore, the
inputs should only be active during safe periods of the machinery’s operating
cycle.
Note:
An internal circuit monitors disparity between the two mute input channels.
If the inputs do not switch within 10 secs. of each other the system will
go into a lockout condition
Terminals
B5/B6 and B7/B8 – dual channel emergency stop circuit - Connect
one channel of the machines emergency stop circuit between terminals B5 and B6
and the second channel between terminals B7 and B8.
Note:
An internal
circuit monitors for short circuits and switching disparity between the two
input channels. If the inputs do
not switch together (within 100ms of each other) the system will go into a
lockout condition. This
configuration meets the requirements for ‘control reliability’ and cannot be
used in a single channel configuration.
Important, if the emergency stop inputs are not used; it is
necessary to link terminals B5 to B6 and terminals B7 to B8.
If not the safety output switches will not energize.
Terminals B9 and B11 – 24V DC supply - Additional
+ 24V DC outputs for connecting to the light curtains etc.
Terminals B10 and B12 – 0V DC supply - Additional
0V DC outputs for connecting to the light curtains etc.
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