Western Reserve Controls, Inc.
1782-JDO User’s Manual
PRELIMINARY
4
1 Overview
WRC’s 1782-JDO is a DeviceNet-to-RS485 serial link communications gateway and protocol
converter that provides a DeviceNet interface to Optomux B1 Brainboards. The JDO allows
the user to easily and conveniently connect and integrate existing B1 devices and their
associated I/O into a DeviceNet system.
Using the 1782-JDO you may communicate with the connected B1's in the same fashion as
the other DeviceNet products in the system. Data may be read/written using either I/O polling
or explicit messaging. Typically real-time data is read and written as I/O by the DeviceNet
Master via Polled I/O and parameters are read and written with the Explicit Messaging
technique.
The JDO gateway has several pre-defined Optomux commands built that it uses to
communicate with the B1 boards. As a user you do not need to know any details about the
Optomux protocol – you simply read and write discrete I/O data in your DeviceNet Master’s
I/O tables. To get started you need to fill in the appropriate configuration Parameters in the
JDO Parameter list to define your B1 Brainboard system and some general set-up attributes
and then place the JDO in your DeviceNet Master’s scan table. The JDO builds its owns
internal B1 scan list and starts communicating with the B1 boards. The JDO then translates
discrete I/O data between the DeviceNet polled I/O data and the Optomux B1 protocol
format.
You can connect up to 10 B1 brainboards to the JDO. The DeviceNet Master reads 3 bytes of
data from the JDO (1 status and 2 input data bytes) and writes 2 bytes of discrete output data
to the JDO for each brainboard.
The 1782-JDO is defined as a Communications Adapter device on the DeviceNet system. It
has a 3-pin plug connector for connection to a RS485/422 converter that then connects to the
to and from host connections of the port on a B1 and a 5-pin pluggable DeviceNet connector
for connections to the DeviceNet network. The serial port is configurable to run up to 38.4
kbaud. The device does auto baud rate selection when it is powered up on the DeviceNet
network. The 1782-JDO has one assigned DeviceNet address, which is set by a 6-position
DIPswitch on the unit. Other JDO parameters are software-configurable and are changed
from their default values by third-party DeviceNet configuration tools. Each 1782-JDO has 2
standard green/red DeviceNet LED’s for module status and network status and two green
LED’s to indicate RS485 transmit and receive activity. The RS485 link may be connected in a
point-to-point fashion to a single device, or to multiple devices in the standard RS485
convention.
This manual applies to 1782-JDO software versions 1.08 and later.