VeEX MPA User Manual page 411

MPA_e_manual_D07-00-129P_RevA00
Protocol Tabs
Pointer Value
Freq Offset
411
An NDF error is registered when the received point value
changes and the NDF flag bits are not toggled.
The Pointer Value indicates the offset between the H1/H2
bytes and the first byte of the Virtual Container (VC) or
Synchronous Payload Envelope (SPE) .
For AU pointers, the Pointer Value consists of the last 10
bits (bits 7 through 16) that span the H1 and H2 bytes,
ranging from 0 to 782.
For TU pointers, the Pointer Value spans the V1 and V2
bytes, whose range varies depending on the LP mapping.
•
TU-11 Pointer Range: 0 to 103
•
TU-12 Pointer Range: 0 to 139
•
TU-2 Pointer Range: 0 to 427
•
TU-3 (AU-4) Pointer Range: 0 to 764
Pointer Values are entered using a keypad. After entering the
new Pointer Value, the Pointer automatically moves to the
new position.
The Pointer Frequency Offset function adjusts the rate at
which Pointer adjustments are needed in the payload.
This type of adjustment simulates network clocks that either
run fast or slow. By adjusting the frequency offset rate, this
forces the network equipment to compensate by
decrementing or incrementing the Pointer bytes.
Entering a positive Frequency Offset causes the Pointer
Value to decrement. This is known as negative frequency
justification.
Entering a negative Frequency Offset causes the Pointer
Value to increment . This is known as positive frequency
justification.
The Pointer Frequency Offset function uses a keypad to
enter a frequency offset ranging from -100.0 ppm to +100.0
ppm.
Entering higher positive or lower negative numbers