Banner EZ-SCREEN­ Safety Light Curtain Systems - Manual (Page 35)

page 35
Banner Engineering Corp. • Minneapolis, MN U.S.A.
www.bannerengineering.com • Tel: 763.544.3164
Installation and Alignment
EZ-SCREEN Grid
Instruction Manual
3.7.3 Machine Primary Control Elements and EDM Inputs
Each of the two Machine Primary Control Elements (MPCE1 and MPCE2) must
be capable of immediately stopping the dangerous machine motion, irrespective
of the state of the other. These two channels of machine control need not be
identical, but the stop time performance of the machine (Ts, used to calculate the
separation distance, see Section 3.3.1) must take into account the slower of the
two channels. Some machines offer only one Primary Control Element. For such
machines, it is necessary to duplicate the circuit of the single MPCE to add a
second. Refer to Figures 3-16 and 3-17 or consult the machine manufacturer for
additional information.
External Device Monitoring: It is strongly recommended that one normally
closed, forced-guided monitoring contact of each MPCE be connected to EDM
inputs (see Figures 3-16 and 3-17). If this is done, proper operation of the
MPCEs will be verified. MPCE monitoring contacts is one method of maintaining
control reliability.
External Device Monitoring Hookup
Terminals 6 and 7 of the receiver terminal block provide connection for the
external device monitoring input. External Device Monitoring (EDM) must be
wired in one of three configurations and must agree with the DIP switch EDM
settings on the receiver (see Section 4.1). One- and 2-channel EDM is used when
the EZ-SCREEN Grid OSSD outputs directly control the energizing and de-
energizing of the guarded machine’s MPCEs.
• One-channel monitoring is a series connection of closed monitor contacts
that are forced-guided (captive contact) from each device controlled by the
EZ-SCREEN Grid. The monitoring contacts should open within 200
milliseconds of the OSSD outputs turning on (a clear condition) and should
close within 200 milliseconds of the OSSD outputs turning off (a blocked
condition) or a lockout will occur (see Diagnostics, Section 5.1). Refer to
Figure 3-18 for 1-channel EDM hookup. Connect the monitor contacts
between +24V dc and EDM1 (terminal 6). Leave EDM2 (terminal 7) open (no
connection). Set the configuration DIP switches to 1, per Section 4.1.
• Two-channel monitoring is a separate connection of closed monitor contacts
that are forced-guided (captive contact) from each device controlled by the
EZ-SCREEN Grid. The monitoring contacts should always change state (both
open or both closed) within 200 milliseconds of the corresponding OSSD
state change (turning on or off) or a lockout will occur (see Diagnostics,
Section 5.1). Refer to Figures 3-16 or 3-17 for 2-channel EDM hookup.
Connect the monitor contacts as shown between +24V dc and EDM1
(terminal 6) and between +24V dc and EDM2 (terminal 7). Set the
configuration DIP switches to 2, per Section 4.1.
• No monitoring. Use this setting initially, in order to perform the initial
checkout; see Section 3.6. If No Monitoring is selected, the user must ensure
that any single failure of the external devices does not result in a hazardous
condition and, in such a case, a successive machine cycle will be prevented
(see Section 1.3, Control Reliability). To configure the system for no
monitoring, set the configuration DIP switches to 2, per Section 4.1, and
connect a jumper (supplied) between EDM1 (terminal 6) and EDM2
(terminal 7).
CAUTION . . .
EDM Monitoring
If configured for “No
Monitoring,” it is the user’s
responsibility to ensure that this
does not create a hazardous
situation.
!
NOTE: MPCE
Monitoring and
Control Reliability
In the U.S., Control Reliability
requires that a single failure does
not prevent a normal stop from
occurring, or issues an immediate
stop command, and the next cycle
is prevented from occurring until
the fault is corrected.
A common method of satisfying
these requirements is the use of
2-channel control with monitoring,
where a normally closed, forced-
guided contact of each MPCE is
wired as described in the section at
right and as shown in Figures 3-16,
3-17 and 3-18.