BINARY SYNCHRONOUS COMMANDS
The BSC-equipped2703 implements up to ten channel
commands, depending on the optional features
installed. These commands are:
Command Code Standard (S)
Command in Hexadecimal or Optional(0) Set Mode 23 S
Enable 27 S
Dial 290* Write 01 S
Read02 S
Prepare06 S
Disable 2F S
Poll09 S
AddressIE 0** Prepare
SearchOE 0** *Requires Autocall feature
**Requires Station-Selection feature
Set Mode
This command is used to condition the SF to the
operating environment required. It results in the
fetching of one byte of control information from main
storage to the control circuitry of the SF.
Set Mode
ccw 23, f'I' f2' f3I 23 I Data Add,." I The bit positions of the byte fAtched from main
storage (its location is designated by the data
follows:56 Bit Position
o
1
2 thru 7
Not used.
When set to 1. If a Read com mand
is be ing executed, an Error Index
byte (EIB) is generated and sent to
main storage im mediate Iy following
the ITB, ETB, or ETX character.
Bits0, 1, 2, 3, 6, and 7 of the EIB
are undefined. Bit 4 of the EIB wi 11
be set if a data check was detected
in the preceding block. Bit 5 of the
EIB will be set if an overrun condi
tion was detected in the precedinghlock. When set to O. No EIB character is
sent to main storage following an
ITB, ETB, or ETX character.
Notused. PROGRAMMING NOTE: After a power-on/power-off sequence
or a system reset, theSet Mode command must be used to
re-establish the operating conditions controlled by theSet Mode command.
Enable
This command, preceded by a Set Mode command,
turns the SF on and makes it operational with the
selected data set or data station (depending on whetherEnable Data Address I 31
Count
323940 4748 63
The BSC-equipped
commands, depending on the optional features
installed. These commands are:
Command Code Standard (S)
Command in Hexadecimal or Optional
Enable 27 S
Dial 29
Read
Prepare
Disable 2F S
Poll
Address
Search
**Requires Station-Selection feature
Set Mode
This command is used to condition the SF to the
operating environment required. It results in the
fetching of one byte of control information from main
storage to the control circuitry of the SF.
Set Mode
ccw 23, f'I' f2' f3
storage (its location is designated by the data
follows:
o
1
2 thru 7
Not used.
When set to 1. If a Read com mand
is be ing executed, an Error Index
byte (EIB) is generated and sent to
main storage im mediate Iy following
the ITB, ETB, or ETX character.
Bits
are undefined. Bit 4 of the EIB wi 11
be set if a data check was detected
in the preceding block. Bit 5 of the
EIB will be set if an overrun condi
tion was detected in the preceding
sent to main storage following an
ITB, ETB, or ETX character.
Not
or a system reset, the
re-establish the operating conditions controlled by the
Enable
This command, preceded by a Set Mode command,
turns the SF on and makes it operational with the
selected data set or data station (depending on whether
Count
32
