Woodward EGCP-2 - Chapter 1. General Information; Overview

Manual 26181 EGCP-2 Communications
Woodward 1
Chapter 1.
General Information
Overview
The EGCP-2 has two communication ports: the inter-control RS-485 port and
the configurable RS-422 port. EGCP-2 controls communicate with each other
over the RS-485 network. This network uses a proprietary protocol and is not
intended to be accessed for information. The configurable RS-422 port protocol
may be selected for one of three options: ServLink communications protocol,
which uses the Woodward PC Tools interface exclusively, Modbus
®
* RTU
protocol, which uses an open protocol used by many third party software
manufacturers, or Upload Setpoints, which is a Microsoft DOS based program
used to transfer setpoint files between the control and a PC.
*—Modbus is a registered trademark of Schneider Automation Inc.
To select which protocol will be used, enter the Sequencing and Comms
configuration menu of the EGCP-2 panel using the proper software password,
and scroll to the menu item labeled “422 Protocol”. The selections under this
menu item are:
1. ServLink
2. Modbus
3. Upload Setpoints
NOTE
Whenever the RS-422 protocol setpoint is changed, the EGCP-2 must be
powered down, then powered up again to reset to the new protocol.
If ServLink is chosen for the protocol selection, the EGCP-2 will communicate in
the ServLink protocol, which is used with the Woodward EGCP-2 HMI software
P/N 8928-364 (see Chapter 2, EGCP-2 HMI Software Installation) or with the
Woodward Watch Window Professional software P/N 8928-800 (see Chapter 5,
ServLink and Watch Window Configuration Software).
If Modbus is chosen, the EGCP-2 will communicate in MODBUS RTU protocol,
and make its information available according to the address list shown in Table
6-2, Modbus Addresses for the RTU Protocol. Also, when the RS-422 Protocol is
set to Modbus, the Modbus Address, Modbus Time-out, and Modbus Reset
menu items of the Sequencing and Communications menu become functional.
If Upload Setpoints is chosen, the EGCP-2 panel will switch to a communications
mode where it is waiting to see characters on the 422 serial port that set it to
transfer the contents of the setpoint file to the PC. This task is run on the PC
using the download.exe DOS program (see Chapter 7, Download.exe Setpoint
Utility for more information).