Programming ( + Consider the example p. 5-41to 5-43 !):

1)Disable PLC:

·Before you will begin with the programming you have to disable the PLC function in the line "PLC is" to avoid starting the program while you are writing it.

2)Put in the program:

·Press the 8 -key or the → -key in the line "Programming..." to change to the sub- menu, where you can put in your program step by step (+ See example p. 5-42).

·A program is composed of single commands (e.g. Selecting a gas valve), which have to be connected logically (e.g. OR-Operator). You have to put in a certain code in every program line for each operator and each command (operand).

·You have to set every operator in the line before the commands that shall be combined. If an intermediate result is not used in the process directly, you have to delete the result buffer ("CLEAR"). So, you can avoid errors of the following logical operations. Each program must end with the operator "-7" ("END of the program").

3)Enable PLC:

·You have to select "Enabled" in the line "PLC is" in the menu "Programmable Logic Control" to start the program.

4)Controlling of the results:

·Press the 8 -key or the → -key in the line "Results..." of the menu "Programmable Logic Control" to change to the submenu "PLC Outputs", where you can control the output status.

Available operators for PLC:

Operator types

 

Operator Description

-1

NOP

No operation (= blank line)

-2

OR

operand to IR

-3

AND

operand to IR

-4

INVERT

the IR (intermediate result)

-5

STORE

the IR to RB (result buffer)

-6

CLEAR

set IR to LOW/OFF/FALSE

-7

END

of the program

Available Commands for PLC (Signal Codes 1 - 359):

 

General Signals

Signal ID

Signal

1

RAM-Fail

2

ROM-Fail

3

Seconds; LOW/HIGH change all 1000 ms

4

Any sample gas valve selected (Channel 1...5)

5

Any zero gas valve (Channel 1...5)

6

Any span gas valve Selected (Channel 1...5)

7

NAMUR-status: Failure (Channel 1...5)

8

NAMUR-status: Maintenance Request (Channel 1...5)

9

NAMUR-status: Function Control (Channel 1...5)

10 - 19

Reserved

5 - 38

NGA 2000

90003482(2) [NGA-e (MLT-Software 3.2.X)] 07/98