Dsc (Non-Sna) Structured Fields; Data Chain Structured Field; Select Ipds Mode - IBM 6400 Programmer's Reference Manual

This query reply indicates the valid data streams for the printer. The structured
field is an inbound field only.

DSC (Non-SNA) Structured Fields

IPDS in the DSC environment requires two structured fields. In addition, two Q
codes for the query reply structured fields are required.

Data Chain Structured Field

This structured field provides a data-chaining function in the non-SNA
environment. This is an outbound field only and must be the first structured field
in the transmission. The format of this field is:

Select IPDS Mode

This structured field selects IPDS in the non-SNA environment. If used with the
data chain structured field, the select IPDS mode field must immediately follow
the data chain structured field. If the data chain structured field is not used, the
select IPDS mode structured field must be the first structured field in the
transmission. This field is an inbound and an outbound field. The format of this
field is:
Byte Value Description
0-1 0006 Structured Field Length
2-3 0F21 Data Chain Indicator
4 Bit 0 Reserved
Bit 1-2 Group
00 = Continue
01 = End
10 = Begin
11 = Only
Bit 3-4 Inbound Control
Always 00 (No Change)
Inbound Data Chaining is Not Valid
Bit 5-7 Reserved (Must be 000)
5 00 Reserved
Byte Value Description
0-1 0006 Structured Field Length
2-3 0F83 Select IPDS Mode
4-5 0000 Reserved
IPDS for Control Units
Appendix B. Summary of IPDS for Control Units
191