Programming precautions – KEYENCE Visual KV Series User Manual

Page 214

Advertising
background image

2.5 Programming Notes

3-190

2

Chapter 2 Instructions

0500

2002

#0010

T000

0500

#0010

T000

A

B

D

E

E

0500

C

A

B

0500

C

D

B

C

0500

0501

A

B

C

0500

A

A

B

D

0500

D

0501

Programming precautions

1. A coil output or timer/counter cannot be connected directly from a bus. When an

output coil or a timer/counter is required, insert a 'b' contact of an unused internal
utility relay, a 'b' contact of an unused special utility relay, or a special utility relay
2002 (always ON) as a dummy.

2. A contact cannot be connected to an output line.

3. Make sure that every contact/coil is located on a path from a bus to an output

line. Make sure that there are no unconnected portions.

4. Make sure that illegal short-circuits are not generated in parallel connections.

5. Circuits including output coils cannot be connected in parallel.

However, parallel connection is enabled when each circuit in parallel connection
is connected to an output line.

6 . When the following program is entered with the programming support software

and sent to the KV, and then read from the KV with the software, reading is
disabled due to a "Reverse Compilation Error".
When a return is included in parallel connection in a ladder program, a
decompilation (reverse compilation) error is generated as shown below.
To prevent this error, change the ladder diagram to eliminate the return, or
separate the parallel connection.

KVNKA Chap 02_4dP.p65

08.3.11, 0:04 PM

190

Advertising