Node Element Descriptor (NED)

The sequence number indicator field (bits 3-4 of the flags byte) contains a code of X'01' to indicate that the sequence number in the NED may not be the sequence number of the processor complex. The first 4 bytes of the sequence number field are used for nonsequenced number purposes. See Table 1.

All FICON® CTC devices for every FICON CTC channel on a processor complex share the processor complex's sequence number; the last 7 bytes of which are stored in the last 7 bytes (bytes 23-29) of the sequence number field.

The information in bytes 18-21 and bytes 30-31 are needed to make FICON CTC devices NED-unique to an operating system.

Programs sending Read Configuration Data commands to either side of an FICON CTC device receive the same NED data.

The NED has the following format:

Table 1. Contents of Node Element Descriptor
Word NED Format
0 Flags Type Class Reserved. Level
1 Type Number
2 Type Number (c) Model Number
3 MN (c) Manufacturer
4 Plant of Mfg. Sequence Number
5 Sequence Number (c)
6 Sequence Number (c)
7 Sequence No. (c) Tag
Flags
X'C8'
Type
X'01'
Class
X'09'
Reserved
B'0000000'
Level
B'0'