Hitachi HSC-2100 Hardware Manual page 10

(chapter 1, page 1-13)
Construct an emergency stop circuit and an interlock circuit outside the
programmable controller. Unless they are so constructed, failure of the
product may result in machine breakdown or accident.
Keep the input/output currents of I/O modules within the maximum permitted
current values. If an overcurrent is allowed to flow in the I/O module, the
component part(s) involved may be damaged, resulting an accident, fire, or
product failure.
(chapter 1, page 1-13)
Do not use a transceiver, cellular phone, or the like near the I/O module.
Such communication equipment generates noise, which may result in malfunction
or system failure.
NOTICE
NOTICE
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