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are identical, these recommendations should be considered as guidelines.
Hardware
Considerations
Caution!
The system designer should be aware that devices in controller systems could
fail and thereby create an unsafe condition.
Programming
Precaution
To conform to ICS Safety Recommendations, checks should be placed in the
controller to ensure that all writable registers that control critical parts of plant or
machinery have limit checks built into the program, with an out-of-limit safe
shutdown procedure to ensure safety of personnel.
ICS 3-304.81 Safety Recommendations:
Consideration should be given to the use of an emergency stop function, which is independent of the
programmable controller.
Where the operator is exposed to the machinery, such as in loading or unloading a machine tool, or where the
machine cycles automatically, consideration should be given to the use of an electromechanical override or other
redundant means, independent of the programmable controller, for starting and interrupting the cycle.
If provision is required for changing programs while the equipment is in operation, consideration should be given
to the use of locks or other means of assuring that only authorized personnel can make such changes.
●These recommendations are intended as safeguards against the failure of critical components and the effects of
such failures or the inadvertent errors that might be introduced if programs are changed while the equipment is in
operation.
● The ICS 3-304.81 Safety Recommendations are reproduced by permission of the National Elec-trical
Manufacturers Association from (NEMA) ICS 3-304.
2.3 Communication Connections and Other Fittings
The ports as you look at the back of the case are the ports for connecting to a Printer, PC, a PLC
or some other peripherals (such as Controller Connectors).
2.3.1 Connection with External Devices
Cable
requirements
Different cables are required for various external devices.
Precaution
Caution!
Do no insert
or pull out
the cable
while the
power is on.
Restrict cable length to less than 150m for RS-485/422 devices and 15m for
RS-232 devices to avoid communications problems.
Communications problems cause the display to show
“PLC no response…” until
communications can be established. The COM light on the front of the EOP4-057 will
turn on with each communication.
Shielded cables must be used for long lengths or cables run in an electrically noisy
environment.
Do not run cables next to AC power lines or near sources of electrical noise.
Be sure that the cable ends have been inserted all of the way into mating connectors
and are secure.
Pin
Designations
COM0 & COM2
Pin assignment of the 9-pin male, D-SUB, COM0. This port is used to connect the
EOP4-057 series to controller with RS-232/485/422 port.
Note:
RS232/485/422 communication functions are supported by COMO.
COM2 supports RS232 communication function, not only can connect with the