Woodward EGCP-2 - Modbus RTU Communications for the EGCP-2 Panel

Manual 26076 EGCP-2 Engine Generator Control Package
Woodward 113
NOTE
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
ports that set it to transfer the contents of the setpoint file to the PC. This
task is run on the PC using the Download_D.exe DOS program. The
Download_D.exe program is available for download on Woodward’s Internet
web page.
1) Go to www.woodward.com/software
.
2) In the box, select EGCP-2 Tools for all EGCP-2 related software available
at present time.
Modbus RTU Communications for the EGCP-2 Panel
The Modbus ID configuration menu item is adjustable from 1 to 247. This
address identifies the Modbus Slave to the Modbus Master using this address.
The Modbus address chosen for any particular EGCP-2 panel should be unique
from any other devices on the Modbus network.
NOTE
The Network Address of the EGCP-2 panel is not linked to the Modbus ID in
any way.
Modbus Time-out is located in the Sequencing and Comms configuration menu.
This item is the time, in seconds, which the EGCP-2 panel will wait before either
receiving a valid message from the Modbus master, or indicating a Modbus
failure. The EGCP-2 panel indicates a Modbus failure in the bottom two lines of
the Modbus Timeout and Modbus Reset Sequencing and Comms configuration
menu items. This display shows Link failure (failure to receive a valid message
from the master) as true/false, and an error number, which is associated with the
type of failure. For example LF-XF 0 is the indication of a healthy Modbus
connection with a Link failure of False and a failure number of 0. The Link failure
is a latching-type indication, and requires the Modbus Reset menu item to be
toggled from True to False in order to reset. See Table 9-3 for a list of common
error numbers that may be seen in the Load Control Monitor Display.
The Modbus Reset is located in Sequencing and Comms configuration menu. It
is used to reset any failures indicated on the Modbus serial communications, and
also to restart the Modbus Time-out timer from zero seconds. The Modbus Reset
should be left at FALSE, and only turned to TRUE to provide a reset action on
the Modbus. Once the reset is accomplished, the Modbus Reset must be taken
back to False once again.
The Modbus communications used by the EGCP-2 panel operate at 9600 baud,
with 8 data bits, 1 stop bit, NO parity, and NO flow control. The protocol used is
Modbus RTU (Master/Slave).