Omron CS1 - Operation Manual Download

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3-5

Section

Fail-safe Circuits

Available Connecting Cables

Customizable

Counter Unit

port

Programming

Device

connection

switch setting

Computer

Serial

communications

mode)

Model number

Length

Peripheral port

IBM PC/AT or

ibl

Peripheral bus

CS1W-CN226/626

2 m/6 m

compatible

Port: D-sub,
9-pin, male

CS1W-CN118 and
XW2Z-200S-CV/500S-CV
(Use XW2Z-

jjj

S-CV

for which ESD
countermeasures have
been taken.)

0.1 m + 2 m/5 m

Note The CS1W-CN225/-CN625/-CN227/-CN627 Connecting Cables and the

FIT10/20 CQM1-CIF11 Connecting Cables cannot be used with the Customiz-
able Counter Unit.

3-5

Fail-safe Circuits

You must set up safety circuits outside of the Customizable Counter Unit to pre-
vent dangerous conditions in the event of errors in the Unit or external power
supply. Take particular care of the following points.

WARNING

Take any safety measures necessary outside of the Unit to ensure the safety of
the system in the event of an error due to Unit malfunction or external factors.
Failure to do so could lead to a serious accident.

•

Provide interlock circuits, limit circuits, emergency stop circuits, and similar
safety measures in the PC’s external control circuits.

•

Operation will stop and all contact and pulse outputs will turn OFF when the PC
detects an error or when a FALS(07) (fatal error) instruction is executed. You
must take any safety measures necessary outside of the Unit to ensure the
safety of the system in the event that all contact and pulse outputs turn OFF.

•

It is possible for an output to remain ON or OFF due to a factors, such as dam-
age to a transistor in the internal circuit of a contact output. Provide any circuits
necessary outside of the PC to ensure the safety of the system in the event that
a contact output fails to turn OFF or ON.

•

If there is an overload or a short-circuit in the Power Supply Unit’s 24-VDC out-
put (service power supply), the voltage may drop and the outputs may turn
OFF. Take any safety measures necessary outside of the Unit to ensure the
safety of the system in the event that outputs turn OFF.

If the PC’s power supply is turned ON after the controlled system’s power supply,
contact outputs may malfunction momentarily and, as a result, the controlled
system’s outputs may operate incorrectly for a short time. To prevent any mal-
function, add an external circuit that prevents the power supply to the controlled
system from going ON before the power supply to the PC itself.

When any of the following fatal errors occur at the Customizable Counter Unit,
the Unit will stop operation (and processing) and all contact outputs and pulse
outputs will be turned OFF:

•

A Unit WDT error, a Unit RAM error, a memory error, a no END instruction error,
a FALS instruction execution, or a CYCLE TIME OVER error

Note For analog outputs, either the value set (maximum value, present value, clear)

with the output hold function in the Unit Setup Area (DM 6614) or 0 V will be out-
put. (For details, refer to 7-7 Analog Outputs.)

Set up safety circuits outside of the Customizable Counter Unit to prevent dan-
gerous conditions in the event of the above errors.

Supply Power to the PC
before Outputs

Unit Errors