Poll/Select Configuration Values

Poll Word

Select Word

Figure 4-1 Poll Word Format

T/C: Configure port as a DCE or DTE:
0 = Port to act as DCE
1 = Port to act as DTE
Max I-field: Maximum number of bytes is the largest acceptable I field. Values from 1 to 10,066 bytes. Note that the backplane mechanism limits the largest possible transmitted size to 10,066 bytes (rather than 16,383).




	NOTE: Some ACC interface cards have limited buffering capacity. Large window sizes should be used with caution, especially with large frame sizes, as the buffering capacity of the ACC interface may be exceeded.

Figure 4-2 Select Word Format

T12: This is the value of the T1 timer (divided by two). The valid range is 1 to 63; 0 is not allowed and is an error. The units are given by the T1 Res (resolution) field (see below).
T1 Res: Resolution of the T1 value above. The values correspond as follows: 0=10ms, 1 = 100ms, 2 = 1s,
3 = 10s
K: Level 2 window size, values 1 to 7. If K=0, then extended sequence numbering will be used, and the window size is configured via the "Extended K" field. If K=0, the link is initialized via a SABME command rather than the SABM command, used for standard sequence numbering.
N2: Number of retransmissions, values 1 to 31. Note that 0 is not allowed and is an error.

Figure 4-3 Option Word Format

IUF: Error handling, normal when 0. This means normal error handling (level 2 link reset) on receipt of unsolicited response frame with F=1. 1 means Ignore F=1 (treat as F=0) in any unsolicited response frames.
Extended K: Window size for extended sequence numbering. When K=0, extended sequence numbering is selected. The Extended K field is used to configure the windows size for modulus 128 sequence numbering. Valid values for this field are from 1 to 127 inclusive.

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