The section below describes the macros for the generation of the control blocks, the structure of the control blocks and the meaning of the fields in the control blocks.
The description adheres to the structure of the corresponding Assembler macro. The layout of the interfaces in C (header files) is described in section “Appendix - C header files”.
Any fields which are not described are intended for internal use by EDT. Users may not modify their contents.
The following overview indicates the assignment of the control blocks to the V16 and V17 formats:
Control block | V16 format | V17 format |
| Version 1 | Version 2 |
| Version 2 | Version 3 |
| Version 1 | Version 2 |
| Version 1 | Version 2 |
| Versions 1, 2, 3 | Version 4 |
On a call, the employed control blocks must either all belong to the V16 format or all belong to the V17 format. Calls containing a mixture of control blocks in V16 and V17 format are rejected.