Rockwell Automation 1756-HSC ControlLogix High Speed Counter Module - Manual (Page 23)

Rockwell Automation Publication 1756-UM007C-EN-P - November 2011
Counter Modes 23
Rollover in Output tag
When using the HSC Data-extended Comm Format while configuring the
module, the Rollover tag will be found in both the Configuration and Output
tag areas.
The Configuration tag value is populated during software configuration with
the Logix5000 controller, and sent to the module upon powerup, defining its
behavior. This value will continue to define module behavior as long as the
corresponding tag in the Output area is zero.
If the value of the Rollover tag in the Output area is changed to a non-zero
value, the module will disregard the value sent from the Configuration area and
use the value in the Output area instead. This facilitates easier real-time
‘on-the-fly’ changes to the Rollover function.
Input Z (Gate/Reset)
Input Z, when active, will change the behavior of an accumulated count value
in the Present Value tag, depending upon which of four modes is selected.
• Store and Continue Mode
• Store, Wait, and Resume
• Store and Reset, Wait, and Start
• Store and Reset, and Start
The Storage modes are selected on the Counter Configuration tab on the
Module Properties dialog box of the RSLogix 5000 programming software.
Storage Modes
The store count feature allows the module to store the current count value and
follow four behavioral paths, depending on which Store mode is selected. The
store count is triggered by the state of the Z-input (the gate) on the module.
The following illustrations show how the different modes store count values in
the Present Value and Stored Value tags.
IMPORTANT
The four modes can be changed while normal module operation
continues. Improper use of on-the-fly changes may cause
unintended machine operation when the store count is used as
a trigger for machine sequencing.