User manual

High-Speed Input and
Pulse Output Features
3--10
High-speed Input and Pulse Output Features
DL105 PLC User Manual, 3 rd Edition
The preset values occupy two data words each. They can range in value from 0000
0000 to 9999 9999, just like the high-speed counter value. All twenty-four values are
absolute values, meaning that each one is an offset from the counter zero value.
The preset values must be individually derived for each application. In the industrial
lathe diagram below, the PLC monitors the position of the lead screw by counting
pulses. At points A, B, and C along the linear travel, the cutter head pushes into the
work material and cuts a groove.
PLC
Industrial Lathe
Start
ABC
Counter
Device
X0, counter clock
Motor
The timing diagram below shows the duration of each equal relay contact closure.
Each contact remains on until the next one closes. All go off when the counter resets.
Equal Relays
SP540
SP541
SP542
ABC
NOTE: Each successive preset must have a greater value than the previous preset
value. In the industrial lathe example, B > A and C > B.
The configurable discrete input options for High-Speed Counter Mode are listed in
the table below. Input X0 is dedicated for the counter clock input. Inputs X1 and X3
can only be filtered inputs. The section on Mode 60 operation at the end of this
chapter describes programming the filter time constants. Input X2 can be configured
as the counter reset, with or without the interrupt option. The interrupt option allows
the reset input (X2) to cause an interrupt like presets do, but there is no SP relay
contact closure (instead, X2 will be on during the interrupt routine, for 1 scan). Or
finally, X2 may be left simply as a filtered input like X1 and X3.
Input Configuration
Register
Function Hex Code
Required
X0 V7634 Counter Clock 0001
X1 V7635 Filtered Input xx06 (xx = filter time)
X2 V7636 Counter Reset (no interrupt) 0007
Counter Reset (with interrupt) 0107
FIltered Input xx06 (xx = filter time)
X3 V7637 FIltered Input xx06 (xx = filter time)
Calculating Your
Preset Values
X Input
Configuration