Epson RC620 Manual page 13

Open Standard (Multi-vendor)
Due to an open communication standard, various devices from many manufacturers are
available.
reconstruction.
Maintenance spare parts stored on site (factory, etc.) can be reduced because different
manufacturers' devices can be used in case of a breakdown. Similar products are available
around the world due to a global standard DeviceNet.
Numbers of Inputs/Outputs
Using a Fieldbus master board, you can control 1,024 inputs (128 bytes) and 1,024 outputs
(128 bytes).
Also, using a Fieldbus slave board, you can exchange 256 inputs (32 bytes) and 256
outputs (32 bytes) with a master.
Communication Types
There are two types of messaging connections: I/O messaging connection and Explicit
messaging connection.
explained below:
Polling
Strobe
Change Of State : A device sends data whenever it changes. Signals for device diagnosis
Cyclic
 NOTE
For Change of State and Cyclic, the ACK which verifies communication completion
can be disabled by setting. However, never disable the ACK since communication
errors cannot be detected.
RC620 Option Fieldbus I/O Rev.8
Standardized communication connectors provide you with easy network
I/O messaging connection includes the following 4 methods
: First, a master device sends output data to a slave device and then the
slave device responds. Data is normally exchanged in every
communication cycle. The communication frequency can be changed
by setting. This connection type is the most often used.
: First, a master device requests slave devices to send data with
multicast messages, and then, each slave device responds individually.
Data from many sensors on the system can be effectively gathered.
When the master does not receive responses from all requested slave
devices, a timeout error occurs.
are sent regularly in the background. This connection type is useful for
remedying DeviceNet communication traffic.
: A slave device transfers data regularly according to its internal timer.
This connection type is typically used for communicating with a
temperature controller. The data transfer frequency is defined by
master configuration.
1. Introduction
3