Using the global task feature – Maple Systems MAPware-7000 User Manual
Page 87
MAPware-7000 Programming Manual
87
1010-1040, Rev. 02
Screen #2 is now complete and should look something like:
We now create a simple ladder logic program using the Logic Block feature of MAPware-7000.
This logic program will simply turn ON the bit lamp in Screen #2, if the value in the Numeric
Entry object (i.e. ‘Boiler Temp’) exceeds or is equal to 100.
To guarantee maximum processing speed, Logic Blocks are not able to directly read registers or
coils from a PLC attached to the HMC7000. To get around this problem, we will create a global
task that continuously reads the value in the PLC register and copies it over to an internal
memory area of the HMC. Then the ladder logic program can simply read the internal memory
area.
Using the Global Task Feature
First, we create the global task:
Click on the Tasks folder in the Project Information Window:
Notice that we already have a ‘Power-On’ task- Go to Screen 1. This is created by
default when a new project is started. A power-on task executes once when the
HMC7000 initially turns on.
Click on the Global Tasks radio button.
Under the Select Task field, click on the pull-down box and scroll through the tasks listed
until you find the Copy HMI/PLC Block to HMI Block task.
For Tag A (HMI), click the pull-down box and select the D00050 (Copy of N7:50) tag.