CA Operating Environment
The CA is used by the 3745 control program (NCP or PEP) to communicate with
an application program in the host(s) through various telecommunication access
methods.
Physically, channel interface tags and buses attach the CA to the host channels,
and IOC buses attach internally the CA to the CCU.
Modes of Operation
The CA can run in either native subchannel (NSC) mode or in emulation sub-
channel (ESC) mode. The CA operates in the following modes:
NSC with the Network Control Program (NCP)
NSC and ESC simultaneously with the Partitioned Emulation Program (PEP)
Notes:
1. With PEP, the NSC is used for loading and dumping.
2. Initial program load (IPL) must always be done in NSC mode.
3. BCCA works only in native mode (NCP).
NSC Mode
The NSC mode is supported for all types of host channel (byte multiplex, selector,
or block multiplex), and allows servicing any number of lines using only one host
subchannel address. Line address decoding is handled entirely by the NCP.
ESC Mode
The ESC mode is supported for byte multiplex channels only, and allows the con-
troller to emulate the 2701 Data Adapter Unit, 2702 Transmission Control, and
2703 Transmission Control using existing host programs and subchannel
addresses. This mode requires the Partitioned Emulation Program (PEP) in the
3745, and a separate subchannel address for each PEP line. The ESC mode is
not supported with BCCA.
Host Unit Control Word (UCW)/Host I/O Configuration Data Set (IOCDS)
The host system UCW/IOCDS requirements for the controller vary according to the
type of control program and features. They are described in the appropriate host
I/O Configuration Program (IOCP) User's Guide and Reference. UCW/IOCDS
requirements are determined as follows:
One UCW/IOCDS is required for each unique NSC address.
An additional UCW/IOCDS is required for each emulated subchannel address.
For example, a controller running PEP with two ESCs needs three
UCW/IOCDS.
All UCW/IOCDS must be unshared and unfolded.
7-8
IBM 3745 Models 130, 150, 160, 170, and 17A: Hardware Maintenance Reference
Содержание 3745 Series
Страница 2: ......
Страница 12: ...x IBM 3745 Models 130 150 160 170 and 17A Hardware Maintenance Reference ...
Страница 14: ...xii IBM 3745 Models 130 150 160 170 and 17A Hardware Maintenance Reference ...
Страница 18: ...xvi IBM 3745 Models 130 150 160 170 and 17A Hardware Maintenance Reference ...
Страница 21: ...3745 Models 130 150 160 and 170 Data Flow Chapter 1 General Information 1 3 ...
Страница 149: ...For RACs 241 to 244 ERR bits Data received from the adapter Chapter 3 Buses 3 57 ...
Страница 166: ...4 14 IBM 3745 Models 130 150 160 170 and 17A Hardware Maintenance Reference ...
Страница 169: ...Chapter 4 Transmission Subsystem TSS 4 17 ...
Страница 255: ...The HPTSS in 3745 Models 130 150 160 and 170 Data Flow Chapter 5 High Performance Transmission Subsystem HPTSS 5 3 ...
Страница 303: ...Figure 6 8 Ring to Ring via Bridge Example 2 Typical Multi Floor Wiring Chapter 6 The Token Ring Subsystem 6 9 ...
Страница 322: ...6 28 IBM 3745 Models 130 150 160 170 and 17A Hardware Maintenance Reference ...
Страница 348: ...7 26 IBM 3745 Models 130 150 160 170 and 17A Hardware Maintenance Reference ...
Страница 625: ...The ESS in 3745 Models 130 150 160 and 170 Data Flow Chapter 12 Ethernet Subsystem ESS 12 3 ...
Страница 668: ...Problem Determination Aid 12 46 IBM 3745 Models 130 150 160 170 and 17A Hardware Maintenance Reference ...
Страница 674: ...X 6 IBM 3745 Models 130 150 160 170 and 17A Hardware Maintenance Reference ...
Страница 708: ......
Страница 711: ......
Страница 712: ...IBM Part Number 03F5010 Printed in Denmark by IBM Danmark A S ð3F5ð1ð SY33 2ð66 4 ...