Mainframe Hardware Definition

Each channel adapter attached to a mainframe channel must be described to the mainframe hardware. Depending on the mainframe type, this is performed with either an IOCP generation, or some other method of defining the CPU's UCWs (Unit Control Words) supported by your mainframe type.

VM has an IOCP MODULE on the system disk which builds the IOCP configuration file for you.

MVS/ESA Version 5 has HCD, an interactive utility which runs under TSO and which will build the IOCP configuration file. 

Please review the IOCP sample definition appropriate for the type of channel-attached controller you are installing:

IOCP examples for a Bus-and-Tag channel adapter serving VTAM 3174 PUs

IOCP examples for an ESCON channel adapter serving VTAM 3174 PUs

Example A: Connection Direct to ESCON Channel (One VTAM PU)

Example B: Connection Direct to ESCON Channel (Multiple VTAM PUs)

Example C: Connection to an ESCON Director in Basic Mode (One VTAM PU)

Example D: Connection to an ESCON Director in Basic Mode (Multiple VTAM PUs)

Bus-and-Tag Adapter Serving VTAM 3174 PUs

For proper operation observe the following IOCP or UCW parameter general requirements:

• The Bus-Tech channel adapter can support up to 32 subchannel (device) addresses. However, NetWare for SAA versions 1.3B, 2.0, and 2.2 can only support a maximum of eight Data Link Adapters (PUs) due to NetWare limitations. IntraNetware for SAA version 3.0 can support a maximum of 32 PUs if all the latest Netware 4.11 PTFs and Service Packs are applied. Microsoft NT SNA Server and IBM Communications Server for NT support up to 32 addresses.
  
• For each PU to be supported by the channel adapter, generate the IOCP or UCW for a separate 3791L control unit with 1 device per controller. Do not define multiple devices on a 3791L control unit. If you use the more modern control unit type of 3174, multiple devices per control unit are supported.
  
• The channel mode in the IOCP or UCW generation must match the channel mode set for the adapter (refer to the channel adapter hardware guide). The channel modes supported by Bus-Tech adapters are DC Interlock, 3.0 MB Streaming, and 4.5 MB Streaming. Your bus-and-tag cables must be rated for streaming, if using Streaming Mode.
  
• The channel adapter UCWs must be generated as nonshared.
  
• For IOCP CNTLUNIT and IODEVICE definitions, specify either UNIT=3791L or UNIT=3174. If using 3791L types, assign only one device per 3791L control unit statement (for each PU, create one set of CNTLUNIT and IODEVICE statements which define a single 3791L device).
  
• If you are using MVS's HCD utility, specify DYNAMIC: NO and LOCANY: NO.
  
• If you wish to run the channel adapter with both SNA 3174 emulation as well as TCP/IP 3172 emulation, then choose a Control Unit type of NOCHECK instead of 3791L or 3174. NOCHECK will bypass the HCD objections that it detects two types of devices on a single controller. The IODEVICE statements still require the appropriate device type of 3791L or 3174 however.

For further information on IOCP or UCW generation methods and parameters, refer to your mainframe CPU documentation.

The following is an example of an IOCP generation for a typical channel attached installation. This particular configuration defines one channel adapter, with two PUs at addresses 5F0 and 5F1.

The IOCP generation is the same for all types of PUs supported by the channel adapter. The PUs supported by the channel adapter are NetWare for SAA PUs, type 2.0 and type 2.1.

If your mainframe (such as an IBM 4381) does not require an IOCP definition, simply configure your UCWs similarly using the method required for your CPU.

Note: If your channel supports streaming mode, then chose the appropriate S or S4 operand on the PROTOCL= parameter. You must also ensure that the channel adapter is configured accordingly. Incorrect matching of the CPU's channel mode and the adapter's channel mode may cause unpredictable errors on the mainframe channel.

For proper operation observe the following IOCP or UCW parameter general requirements:

• The Bus-Tech ESCON adapter can support up to 32 subchannel (device) addresses. However, NetWare for SAA versions 1.3B, 2.0, and 2.2 can only support a maximum of eight Data Link Adapters (PUs) due to NetWare limitations. IntraNetWare for SAA 3.0 can support a maximum of 32 PUs if all the latest NetWare 4.11 PTFs and Service Packs are applied. Microsoft NT SNA Server and IBM Communications Server for NT support up to 32 addresses.
• For IOCP CNTLUNIT and IODEVICE definitions, specify UNIT=3174.
• There is no PROTOCL= used for ESCON devices; ESCON uses a constant channel speed.

For further information on IOCP or UCW generation methods and parameters, refer to your mainframe CPU documentation.

The following are examples for creating the Mainframe IOCP Generation for an ESCON Adapter connecting directly to an IBM ESCON channel.

Example A: CONNECTION DIRECT TO ESCON CHANNEL (ONE VTAM PU)

The following example shows a configuration of one subchannel address, x'2F0', (i.e. one VTAM PU) generated on the adapter connected to a mainframe using CHPID 21:

Example B: CONNECTION DIRECT TO ESCON CHANNEL (MULTIPLE VTAM PU's)

The following example shows a configuration of three subchannel addresses, x'380'-x'382', (i.e. three VTAM PUs) generated on the adapter connected to a mainframe using CHPID 19:

Example C: CONNECTION TO ESCON DIRECTOR IN BASIC MODE (ONE VTAM PU)

The following example shows a configuration of one subchannel address, x'2F0', (ie,one VTAM PU) generated on the adapter connected to a mainframe using CHPID 22 through an ESCON director:

Example D: CONNECTION TO ESCON DIRECTOR IN BASIC MODE (MULTIPLE VTAM PU'S)

The following example shows a configuration of three subchannel addresses, x'7F0'-x'7F2', (ie, three VTAM PUs) generated on the adapter connected to a mainframe using CHPID 22 through an ESCON director: