64
CHAPTER 12: DOWNLOADABLE COMMUNICATION PROTOCOLS
12.1 Overview
Through loadable protocol device drivers, certain models of the i3 family can provide the ability to
exchange data with remote devices such as variable-frequency drives, PLCs, and remote I/O devices. This
feature greatly expands the i3 ’s control capability with negligible effect on the i3 ’s ladder scan time.
Remote devices that communicate serially must do so under certain rules of data transfer known as a
protocol. Many device manufactures have created their own protocol for communications with their
device. For an i3 to communicate with a specific device, it must be loaded with the corresponding serial
communications protocol device driver that supports that protocol.
A limited number of protocol device drivers are packaged with the i3 configurator distribution; however,
as more are developed, they will be made available as add-on packages. A device driver is typically
distributed as a Windows module, which contains the Configuration Menus, Help Files, and the Target
Executable Driver Code. When updating device drivers, an install routine loads the device driver to the i3
configurator directory structure and makes that driver available to I3 configurator applications.
Once installed, the protocol device driver can be included as part of a i3 configurator application by
selecting it from a list of installed protocol device drivers and attaching it to the desired serial port
(Program > Protocol Config menu). Only one protocol device driver can be associated with a serial port,
though some I3 models support multiple protocols on a single Ethernet port.
Once the protocol is selected for a specific port, that port must be configured to match the bit transfer
size and rate of the target device(s). This is configured under the
Network Config
menu, which contains
port specific information such as the basic serial port parameters (i.e. baud rate, stop bits parity, retries,
etc.). In addition to the serial port parameters, this menu also contains the transaction scan update control
configuration and any network level protocol specific configuration.
Once the network is configured, each device on the serial communications network must be configured.
For some communications (i.e. RS232), the network can be limited to one device. The devices are
configured under the
Device Config
menu, which contains an arbitrary device name, the device ID and
optionally an I3 status register that contains any device fault information.
Once each device(s) is configured, a
Scan List
of entries must be created which defines the transfer of data
between a local (I3) register(s) and a remote device register(s). These entries are created under the
Data
Mapping
menu, which contains an I3 register, a target device ID, a target device register address, the
number of registers to transfer, and update type.
Содержание i3N Series
Страница 1: ...Think inside the box User Manual For i3 N Series Controllers...
Страница 39: ...39...
