Ladder Diagrams and Instruction List - Lesson

The following Lesson is associated with Mitsubishi FX series PLC

Lets start by looking at the Instruction List Code for the above PLC

Instruction List Code
LD Begin a new rung (also new load) with a Normally Open contact
LDI Begin a new rung (also new load) with a Normally Closed contact.
AND Connect a Normally Open contact in series with an existing contact.
ANI Connect a Normally Closed contact in series with an existiong contact.
ANB Join a new completed parallel connected block in series with an existing one.
OR Connect a Normally Open contact in parallel with an existiong contact.
ORI Connect a Normally Closed contact in parallel with an existing contact.
ORB Complete the right hand connections of a parallel connected block of contacts.
OUT Connect to an output device. (output relay - internal relay - timer )

 

Examine the following list of Ladder Diagrams and their associated Instruction List:

Just one Normally Open contact and its associated Instruction List.

Lets move on and add a n/o contact in series with the above contact.

and a third N/O Contact in series. (notice the 3 lines of code)

Upgrade to view up to Ladder Diagram 26

Last modified: Wednesday, 15 May 2013, 06:49 PM