Hamilton Sundstrand Company Fuel Metering Valves XVG Manuel D’Utilisation

 

 

 

 

The primary interface used for XVG/eXVG is serial communication, which is the 
exchange of data one-bit-at-a time, sequentially, on a single data line or channel.  
XVG/eXVG can communicate either in PECC (a propriety standard protocol) or 
Modbus protocol via the serial interface.    

 

Baud rate is the speed at which a data line changes its state or the number of times per 
second the line changes state.  If two serial devices are connected together via direct 
cables, then baud rate and bit-per-second are the same.  XVG/eXVG Modbus 
communication supports baud rates of 9600, 19200, 38400, and 57600. 

 

A parity bit is optionally transmitted along with data to help detect data corruption 
that may occur during transmission.  There are three parity modes available:  Odd, 
Even, or None.  XVG/eXVG Modbus communication default parity setting is Even. 

 

 

The start bit informs the receiving device that a character is coming; a stop bit 
indicates that a character is completed.  The start bit is always 0 and stop bit is always  
1.  Per Modbus protocol requirements, XVG/eXVG Modbus communication employs 
1 stop bit in Even or Odd parity mode, and 2 stop bits in None parity mode. 

 

 

XVG/eXVG serial communication uses either RS232 for one-to-one connection or 
RS485 for a multi-drop capable network. 

 

-  RS232 interface uses three wires:  transmit, receive, and common (ground) line.  

A -3 to -12V signal indicates a 1, a +3 to +12V signal indicates a 0.  
Communication is one-to-one, and full-duplex capable.  Distance is limited to 
50 feet. 
 

-  RS485 interface uses two wires:  T+/R+ and T-/R-.  The RS485 receiver 

compares the voltage difference between both lines instead of the absolute 
voltage level on a signal line.

 

Communication is half-duplex and up to 32 

devices can be connected to a multi-drop network up.  Distance is limited to 
4000 feet. 

 

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