Siemens S7-1200 - Recipes and Data Logs; Recipes; Recipe Overview

Extended instructions
8.7 Recipes and Data logs
S7-1200 Programmable controller
System Manual, 03/2014, A5E02486680-AG
369
The default locations for the pulse width values are as follows:
● PWM1: QW1000
● PWM2: QW1002
● PWM3: QW1004
● PWM4: QW1006
The value at this location controls the width of the pulse and is initialized to the "Initial pulse
width:" value specified above each time the CPU transitions from STOP to RUN mode. You
change this Q-word value during run time to cause a change in the pulse width.
8.7
Recipes and Data logs
8.7.1
Recipes
8.7.1.1
Recipe overview
Recipe data storage
● A recipe data block that you create in your project must be stored in CPU
load
memory.
Internal CPU memory or an external memory "Program" card can be used.
● Another DB that you must create is the active recipe data block. This DB must be in
work
memory, where one active recipe record is read or written with your program logic.
Recipe data management
The recipe DB uses an array of product recipe records. Each element of the recipe array
represents a different recipe flavor that is based on a common set of components.
● You create a PLC data type or struct that defines all the components in one recipe record.
This data type template is reused for all recipe records. Product recipes vary according to
the start values that are assigned to the recipe components.
● One of the recipes can be transferred at any time from the recipe DB (all recipes in load
memory) to the active recipe DB (one recipe in work memory) using the READ_DBL
instruction. After a recipe record is moved to work memory, then your program logic can
read the component values and begin a production run. This transfer minimizes the
amount of CPU work memory that is required for recipe data.
● If the active recipe component values are adjusted by an HMI device during a production
run, you can write the modified values back to the recipe DB, using the WRIT_DBL
instruction.