Route list format
BMS requires a fixed format for route lists. Each entry in the list is 16 bytes long.
| Bytes | Contents |
|---|---|
| 0-3 | Terminal or logical unit identifier (four characters, including trailing blanks), or blanks |
| 4,5 | LDC mnemonic (two characters) for logical units with LDC support, or blanks |
| 6-8 | Operator identifier, or blanks |
| 9 | Status flag for the route entry |
| 10-15 | Reserved; must contain blanks |
Either a terminal or an operator identifier must be present in each entry. A Logical Device Component(LDC) may accompany either; see LDCs and routing in Logical device components for more information about LDCs.
The entries in the route list normally follow one another in sequence. However, they do not all have to be adjacent. If you have a discontinuity in your list, you end each group of successive entries except the last group with an 8-byte chain entry that points to the first entry in the next group. This entry looks like this:
| Bytes | Contents |
|---|---|
| 0,1 | -2 in binary halfword format (X'FFFE') |
| 2,3 | Reserved |
| 4-7 | Address of the first entry in the next group of contiguous entries |
The end of the entire list is signalled by a 2-byte entry containing a halfword value of -1 (X'FFFF').
Your list may consist of as many groups as you want. There is an upper limit on the total number of destinations, but it depends on many variables; if you exceed it, BMS abends your task with abend code ABMC.
- RTESOME
- means that at least one of the entries in your route list could not be used and was skipped. The default action is to continue the routing operation, using the destinations that were processed successfully.
- RTEFAIL
- means that none of the destinations in your list could be used, and therefore no routing environment has been set up. The default action is to return control to your task. You should test for this condition, consequently, because with no routing environment, a subsequent BMS SEND command goes to the principal facility, which is probably not your intention.
In addition to the general information reflected by RTESOME and RTEFAIL, BMS tells you what it did with each entry in your list by setting the status flag (byte 9). A null value (X'00') means that the entry was entirely correct. The high-order bit tells you whether the entry was used or skipped, and the other bits tell you exactly what happened. Here are the meanings of each bit being on:
- ENTRY SKIPPED (X'80')
- The entry was not used. When this bit is on, another bit is also on to indicate the reason.
- INVALID TERMINAL IDENTIFIER (X'40')
- There is no terminal definition for the terminal named in the entry. The entry is skipped.
- TERMINAL NOT SUPPORTED UNDER BMS (X'20')
- The terminal named in the route list entry is of a type not supported by BMS, or it is restricted from receiving routed messages. The entry is skipped.
- OPERATOR NOT SIGNED ON (X'10')
- The operator named in the entry is not signed on. Any of these
conditions causes this flag to be set:
- Both an operator identifier and a terminal identifier were specified, and the operator was not signed on at the terminal. The entry is not skipped.
- An operator identifier was specified without a terminal identifier, and the operator was not signed on at any terminal. The entry is skipped.
- OPCLASS was specified on the ROUTE command, a terminal identifier was specified in the route list entry, and the operator signed on at the terminal did not have any of the specified operator classes. The entry is not skipped.
- OPERATOR SIGNED ON AT UNSUPPORTED TERMINAL (X'08')
- Only an operator identifier was specified in the route list entry, and that operator was signed on at a terminal not supported by BMS or not eligible to receive routed messages. The entry is skipped. The name of the terminal is returned in the terminal identifier field of the entry.
- INVALID LDC MNEMONIC (X'04')
- Either of these conditions causes this flag to be set:
- The LDC mnemonic specified in the route list is not defined for this terminal. That is, the terminal supports LDCs but it has no LDC list, or its LDC list is extended but does not contain this entry.
- The device type for this LDC entry is different from that of the first entry in the route list with an LDC (only one LDC device type is allowed, as explained in LDCs and routing in Logical device components).