Delta DVP-ES3 Series Hardware Manual

Chapter 12 CPU Module Operating Principle
12-3
12_
12.1.2 I/O Refreshing and Communication Service
 Refreshing I/O
The CPU module reads external I/O data periodically or outputs data to an external I/O. Refreshing the
I/O includes the following.
 Refreshing data in a digital I/O module
 Refreshing data in analog I/O, temperature measurement and positioning modules
All I/O refreshing executes in the same loop. The data in an input device refreshes before a program
executes, and the data in an output device refreshes after the program executes.
Unit Maximum data exchange Data exchange area
Digital I/O module
Depends on the number of input/output
channels in the unit.
Input relay/Output relay
Analog I/O module
Depends on the number of input/output
channels in the unit.
Data register*
* Refer to special extension module exchange function from section 2.2.16 of DVP-ES3/EX3/SV3/SX3
Programming Manual for more information.
 Communication service
Communication service is the unscheduled communication service for a network module. It includes the
communication requests sent from external equipment to a CPU module, and the communication
requests sent from the CPU module to the external equipment. The communication requests may be
received from time to time but the data or state refreshing on the devices or components will only start
afer the END instruction is scanned and executed if the coummunicaiton is concerning the internal
devices or components of the PLC CPU.
12.1.3 Execution Timing of Interrupts
Interrupts can be categorized into three types, periodic interrupts, timer interrupts, and condition interrupts. The
timing to execute any interrupt is after the current executing instruction is complete and the position and state of
the next to be executed instruction is retained. After the interrupt is executed, the execution of the next
instruction will resume.

Delta DVP-ES3 Series Specifications

General

Brand	Delta
Model	DVP-ES3 Series
Category	Controller
Language	English