EXFO FTB-8100 Series Transport Blazer for FTB-500 - Manual (Page 221)

OTN Tabs
SONET/SDH Application 207
OPU OH RX
PSI Overhead Bytes
Note: The PSI Overhead bytes are only available for OPU3, OPU2, and OPU1 with
ODU mux.
PSI [0] (PT): Displays the received Payload Structure Identifier (Payload
Type). See Payload Type on page 197 for more information.
PSI [2] to PSI [17] bytes: For OPU3, displayed the received Payload
Structure Identifier bytes. The first two bits are indicate the ODU mapping
type while the remaining bits indicate the tributary port numbers.
Note: PSI [2] and PSI [3] and Tributary port 1 and 2 are supported with OPU1.
PSI [2] to PSI [5] and Tributary port 1 to 4 are supported with OPU2.
PSI [2] to PSI [17] and Tributary port 1 to 16 are supported with OPU3.
Next/Previous button, available with ODU3, allows to respectively access
the next (bytes 18 to 33) or previous (bytes 1 to 17) PSI Overhead bytes.