AutomationDirect DL105, User Manual

Page: 79 / 350

High
-S
peed
Input
and
Pulse
O
utput
Features
3--3
High-Speed Input and Pulse Output Features
DL105 PLC User Manual, 3rd Edition
The internal CPU’s main task is to execute the ladder program and read/write all I/O
points during each scan. In order to service high-speed I/O events, the DL105
includes a special circuit which is dedicated to a portion of the I/O points. Refer to the
DL105 block diagram in the figure below.
Output Circuit
Input Circuit
CPU
10 Discrete Inputs
8 Discrete Outputs
PLC
DL105
High-Speed
I/O Circuit
X0 -- X3
Y0, Y1
X4-- X11
Y2 -- Y7
The high-speed I/O circuit (HSIO) is dedicated to the first four inputs (X0 -- X3) and
the first two outputs (Y0 -- Y1). We might think of this as a “CPU helper”. In the default
operation (called “Mode 60”) the HSIO circuit just passes through the I/O signals to
or from the CPU, so that all ten inputs behave equally and all eight outputs behave
equally. When the CPU is configured in any other HSIO Mode, the HSIO circuit
imposes a specialized function on the portion of inputs and outputs shown. The
HSIO circuit operates independently of the CPU program scan . This provides
accurate measurement and capturing of high-speed I/O activity while the CPU is
busy with ladder program execution.
After choosing the appropriate HSIO mode for your application, you’ll need to refer to
the section in this chapter for that specific mode. Each section includes wiring
diagram(s) to help you connect the High-Speed I/O points correctly to field devices.
An example of the quadrature counter mode diagram is shown below.
Encoder Input Wiring
+
--
12 -- 24 VDC
Phase A
Phase B
Encoder
Signal Common
Dedicated High-
Speed I/O Circuit
Wiring Diagrams
for Each HSIO
Mode