Hamilton Sundstrand Company Fuel Metering Valves XVG - Manual (Page 34)

Perform the following steps to retrieve the fault records:
1. Read register 3045, IDM_RECORDS, to get the current number of fault
records available in the XVG/eXVG. The records are named 0, 1, 2, .. , n-1.
Maximum n = 16.
2. To retrieve first record, record 0, write 0 to register 3043,
IDM_FRECORDNO.
3. Write 4 to register 3094, IDM_TESTCTRL.
4. Read registers 3028, 3029, 3044, 5026, 5028, 7050-7072 to complete record
0.
5. Repeat steps 2, 3, 4, and 5, to retrieve record 1, 2, .., n-1.
10.3 Change Gas Constant R and K Procedure
Register
Number
XVG/eXVG Parameter Name Description Type
Write
Access
3005 IDM_SETUPCONNECT
Setup Mode: 1=Set Valve in Setup State, 2=Exit
Setup and Reset CPU
U16 W1
3033 IDM_CALFLAGS Calibration Flags U16 W1
3099 IDM_TESTSTR
Test string, used for Modbus write access
password.
U16 W0
7008 IDM_MEASFLOW Measured Flow, PPH Float Read
7518 IDM_CONSTR
R Gas Constant: must be non-zero, default is
Air, 53.34
Float W0
7520 IDM_CONSTK
K Gas Constant: must be non-zero, default is
Air, 1.4
Float W0
Table 25: Parameters for Gas Constant R and K
Perform the following steps to change gas constant R and K in real-time.
1. Read registers 7518, 7520, and 7008, to get the R, K, and corresponding
measured flow values. Take note of the R and K values for reference. The
only way to restore the default values without a valve close and reset (engine
shutdown) is to write those values into the valve again.
2. Write registers 7518 and/or 7520 with appropriate new values.
3. Read register 7008 to get new measured flow value.
4. Read the registers that are of interest to your application.
5. If desired, save the new R and K value to the valve. Note that the following
SAVE or RESET procedure will CLOSE and RESET the valve.
SAVE Parameters routine:
- Write a password to register 3099.
- Write 1 to register 3033. Wait 100 milliseconds.
- Write 32 to register 3033. Wait 100 milliseconds.
- Write 1 to register 3005. Wait 100 milliseconds.
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