VeEX MPA User Manual page 291

MPA_e_manual_D07-00-129P_RevA00
Protocol Tabs
The Transmit PTR (Pointer) screen contains the following STS Pointer and VT Pointer
options:
VT Pointers are only available when a VT mapping is selected.
Function
NDF Flag
Pointer Value
291
Description
The NDF Flag allows you to specify whether the NDF bits are
set when a new Pointer value is present in the generated
signal.
The following options are available:
Yes (On): Generates an NDF when a new Pointer is
transmitted.
No (Off): Disables NDF functionality.
When the NDF Flag setting is On, then the NDF bits are
toggled when a new Pointer value is transmitted, alerting the
receiving device to expect a change in the pointer value.
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 STS 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 VT pointers, the Pointer Value spans the V1 and V2
bytes, whose range varies depending on the VT mapping.
•
VT-1.5 Pointer Range: 0 to 103
•
VT-2 Pointer Range: 0 to 139
•
VT-6 Pointer Range: 0 to 427
Pointer Values are entered using a keypad. After entering the
new Pointer Value, the Pointer automatically moves to the
new position.