HP 98628A User manual

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HP Computer Systems
HP 98628N98691A
Datacomm Interface Installation
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Fho- HEWLETT
a:~ PACKARD
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F/iOW HEWLETT
a:~ PACKARD
warranty Statement
Hewlett-Packard products are warranted against defects in
materials and workmanship. For Hewlett-Packard Desktop
Computer Division products sold
in the U.S.A. and Canada,
this warranty applies for ninety (90) days from the date of
delivery.* Hewlett-Packard will, at its option, repair or replace
equipment which proves to be defective during the warranty
period. This warranty includes labor, parts, and surface
travel costs,
if any. Equipment returned to Hewlett-Packard
for
repair must be shipped freight prepaid. Repairs
necessitated by misuse of the equipment. or by hardware,
software, or interfacing not provided by Hewlett-Packard are
not covered by this warranty.
HP warrants that its software and firmware designated by HP
for use with a CPU will execute its programming instructions
when properly installed
on that CPU. HP does not warrant
that the operation of the
CPU, software, or firmware will be
uninterrupted or error free.
NO OTHER WARRANTY IS EXPRESSED OR IMPLIED,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
A PARTICULAR PURPOSE. HEWLETT-PACKARD SHALL
NOT
BE LIABLE FOR CONSEQUENTIAL DAMAGES.
*For other countries, contact your local Sales and Service
Office to determine warranty terms.

HP 98628A198691A
Datacomm Interface Installation
for HP Series 200 Computers
Manual Part No. 98628-90001
© Copyright Hewlett -Packard Company 1982, 1983, 1985
This document refers to proprietary computer software which is protected by
copyright. All rights are reserved. Copying or other reproduction of this program
except for archival purposes is prohibited without the prior written consent of
Hewlett-Packard Company.
Hewlett-Packard
Roseville Networks Division
8000 Foothills Boulevard
Roseville, California 95678

ii
Printing History
New editions of this manual will incorporate all material updated since the previous edition.
Update packages may
be issued between editions and contain replacement and additional
pages to be merged into the manual by the user. Each updated page will be indicated by a
revision
date at the bottom of the page. A vertical bar in the margin indicates the changes on
each page. Note that pages which are rearranged due to changes on a previous page are not
considered revised.
The manual printing date and part number indicate its current edition. The printing date
changes when a new edition is printed. (Minor corrections and updates which are incorporated
at reprint do not cause the date to change.) The manual part number changes when extensive
technical
changes are incorporated.
First Edition .............................................. '" November 1982
Update 1 ........................................................ October 1983
Reprint (incorporating update 1) .......................... October 1983
Update 2 ...................................................... December 1983
Reprint (incorporating update 2) ........................ December 1983
Update 3 ....................................................... February 1985

Table ofContents
Chapter 1: General Information
Introduction . . . . . . . . . . . . . . . . . . .
.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1
Unpacking
and Inspection ..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2
Handling
................................................................... 2
Technical Spcifications
....................................................... 3
Product Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3
Cable Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. 4
Specialized Adapters
...................................................... 6
Chapter 2: Interface Configuration
Configuration Switches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. 7
Interrupt Level
and Select Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8
Remote Switch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. 8
Interrupt Level. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. 8
Interface Select
Code ..................................................... 8
Protocol Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10
Async/Data Link Protocol Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10
Async Protocol Default Configuration ....................................... 10
Data Link Protocol Default Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11
Interface Installation . . . . . . . . . . . .
.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12
Chapter 3: Interface Cables
RS-232C Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 13
Optional Drivers and Receivers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 13
Option 001 DTE (Male) Cable ............................................. 14
Option 002 DCE (Female) Cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 15
Connecting Two Desktop Computers
....................................... 16
Using DCE Cables to Connect to DTE Devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17
RS-449 Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. 17
Option 003 RS-423 Unbalanced OTE Cable ................................. 17
Test Connectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. 19
RS-232C DTE Cable Test Connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. 19
RS-232C DCE Cable Test Connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19
RS-449 Cable Test Connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 20
Building Custom Cables ..................................................... 21
Safety Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. 21
Using Interface Power Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 21
Balanced Versus Unbalanced Connections
.................................. 21
Comparison of Datacomm
Standards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 23
iii

iv
Chapter 4: Service Information
Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 25
Z-80A System Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 26
Select Code Recognition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 26
Interrupt System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 27
Interface Reset .......................................................... 27
Shared Memory Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 28
Addressing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 28
Read/Write Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 28
Clock Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 28
Memory Access Select Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 29
Memory Cycle Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 29
Hardware Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 31
Shared RAM ........................................................... 32
Default Switches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33
Baud Rate Multiplexer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33
Line Drivers and Receivers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33
Replacement Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 34

Chapter 1
General Information
Introduction
The HP 98628A Data Communications Interface and HP 98691A Programmable Datacomm
Interface are microprocessor-based datacomm interfaces designed for use with HP Series
200
computers. Each interface contains a built-in microprocessor and associated circuits that per-
form
all protocol management and signalling functions for data communications using RS-
232C and RS-449 connections.
The HP 98628A Datacomm Interface supports two protocols:
• Asynchronous (Async) protocol commonly used for timesharing and remote host compu-
ter applications as well as connections to remote terminals.
• HP DSN/Data Link Protocol most commonly used with Data Link network applications
based
around an HP 1000 network host computer.
The HP 98691A Programmable Datacomm Interface
is designed for installing custom protocols
or protocols that are designed
and supported by suppliers other than Hewlett-Packard Com-
pany. This interface
is usually sold through the supplier of the custom protocol firmware.
Several cable options are also available, accommodating most popular interconnections to
standard datacomm links
and modems. They are discussed in Chapter 3.
1

2 General Information
Unpacking and Inspection
If the shipping carton is damaged, ask the carrier's agent to be present when the interface is
unpacked. If the interface is damaged or fails to operate properly, notify the carrier, and the
nearest
HP Sales and Service Office immediately if your interface is an HP 98628. Retain the
shipping carton for the carrier's inspection. The sales
and service office will arrange for the
repair or replacement of your interface without waiting for the claim against the carrier to
be
settled. If your interface is an HP 98691 Programmable Datacomm Interface, contact the
interface supplier for assistance in repair
or replacement.
Handling
Precautionary measures should be taken to protect interface printed circuit assemblies from
static discharge during handling. Each interface
is shipped in a protective anti-static bag which
provides
adequate anti-static protection for the interface as long as it remains inside the bag. It is
good practice to use additional anti-static protection, such as commercially available personnel
grounding straps when servicing or installing interfaces, memory boards, and other assemblies
that may
be sensitive to electro-static discharge.
Avoid touching integrated circuit leads while picking
up or handling the interface. Static dis-
charge through the leads can easily destroy sensitive components. Handle the
board by the
card edges
or metal backplane cover plate. Do NOT handle the interface by its backplane edge
connector. If the edge connector inadvertently gets dirty, it can be cleaned by using a cotton
swab
and isopropyl alcohol.

General Information 3
Technical Specifications
Product Description
The HP 98628A and 98691A are microprocessor-based (Zilog Z-80A or equivalent) data
communications interfaces that fit the 110 backplane of HP Series 200 computers. The interface
includes
on-board read-write (RAM) memory for buffering and other needs. The microp-
rocessor performs protocol
management and other data communication functions, freeing the
mainframe processor for
other tasks. Protocol(s) supported by the interface depend on what
programs are stored in the Program ROM that is plugged into the socket on the interface card.
Physical Description
Size: 135 mm by 170 mm (5.3 in by 6.6 in)
Weight: 310 grams (11 ounces)
Environmental Range
Temperature: O°C to 45°C (32 to 113°F)
Humidity: 0 to 80% non-condensing
Electrical Specifications
98628A power consumption (typical)
+5 V@ 710 rnA
+12 V @ 37 rnA
-12 V @ 60 rnA
The following adapters also obtain power through the HP 98628 interface. Their consumption
should
be added to the interface power consumption when they are used. Typical values are
shown.
HP 13264A Data Link Adapter:
+5 V @30mA
+ 12 V @ 160 rnA
-12 V @ 23 rnA
HP 13266A Current Loop Adapter:
+5 V @ 200 rnA
+ 12 V @ 90 rnA
-12 V @ 80 rnA
HP 13265A Modem:
+5 V @ 100 rnA
+ 12 V @ 45 rnA
-12 V @ 45 rnA
Electrical Interface Compatibility (with appropriate cables)
RS-232C (similar to CCITT V.24/V.28)
RS-449/RS-423 (similar to CCITT V.10)
RS-449/RS-422 (similar to CCITT V.11)1
1 RS-422 cables for this interface are not available from Hewlett-Packard Company

4 General Information
RS-232C Data Rates
Up to 19,200 baud
RS-449 Data Rates
Data rate limitations for RS-449 applications are dependent on cable length, but generally
exceed
the maximum rates available to RS-232C installations. The following charts show the
maximum
speed versus cable length for RS-422 (balanced) and RS-423 (unbalanced) RS-449
installations:
Cable Length
(feet)
10K
4K
1K
400
100
40
10
10K
Not Recommended
Recommended Combinations
100K
1M
10M
RS-422 Modulation Rate Versus Cable Length
Data Rate
(bits/second)

General Information 5
The waveshaping used
on the datacomm interface force a reduction in the maximum data rates
that can be used for unbalanced transmissions. These limits are allowed by the RS-423 stan-
dard,
and are indicated by the dotted lines in the following chart:
Cable Length
(feet)
10k
4K
1K
400
100
40
10
Not Recommended
Recommended Combinations
Data Rate
100 1K 10K 45K 100K (bits/second)
RS-423 Modulation Rate Versus Cable Length
RS-423 cables are discussed in Chapter 3.
Cable Options
The HP 98628 and 98691 interfaces are available with 3 cable options which can also be
ordered separately. Cable length is approximately 4.9 metres (16 feet). Cables are discussed in
detail in Chapter 3.
Option 001: RS-232C DTE Cable with 25-pin Male Connector
Used to connect to RS-232C DCE devices such as modems. Also available separately as part
number 5061-4215.
Option 002: RS-232C DCE Cable with 25-pin Female Connector
Used to connect to male RS-232C DTE device cables. Connects to 5061-4215 or other termin-
al cables. Available separately as part number 5061-4216.
Option 003: RS-423 DTE Cable with 37-pin Male Connector
Unbalanced connections to RS-449/423 modems or other DCE devices. Available separately
as part
number 5061·-4250.

6 General Information
t .h~ .. ~." ... <~ {", '(t<~
" ' ~ f ~ ,$ "
Option 001 Male Connector Option
002 Female Connector
Specialized Adapters
Three specialized adapters are available for use with the 98628A. They provide a means for
connecting the
98628A to various data communications devices or links, and include the
following:
• HP 13264A Data Link Adapter
• HP 13265A Modem
• HP 13266A Current Loop Adapter
Here
is a brief description of each adapter:
The
HP 13264A Data Link Adapter converts RS-232C signals from the 98628A to the differen-
tial signal levels required for
HP DSN/Data Link connections.
The
HP 13265A Modem is a Bell 103/113-compatible asynchronous modem for connecting
directly to the
US switched (public) telephone network. This modem is originate only, and is
used in applications requiring up to 300 baud communications rates. It supports both auto dial
and manual originate capability.
The
HP 13266A Current Loop Adapter provides a 20 rnA current loop interface for the
98628A. Current loop
is used in applications that require data communications over longer
distances than are possible with standard RS-232C. It
is also used in electically noisy environ-
ments.
The Current Loop Adapter can be configured with active or passive driver and receiver
elements.

Chapter 2
Interface Configuration
The datacomm interface is configured by use of two switch clusters located along one side of
the interface card.
These switches must be set to their proper positions before the interface is
installed in the computer. This chapter discusses how to configure the interface for the various
available options.
This
chapter explains how to configure the HP 98628A Option 100 (Async/Data Link protocol)
Datacomm Interface. If
you are installing an HP 98691A Programmable Datacomm Interface
(interface firmware designed by a supplier
other than Hewlett-Packard Company), configure
the select
code and hardware interrupt level as described in this chapter, then configure the
protocol switches using instructions provided by the supplier of the firmware that is installed on
the interface card.
Configuration Switches
As shown in the following figure, the left-hand switch cluster is used to set the hardware
interrupt level
and interface select code. The left-most switch in that cluster has a function that is
dependent on protocol and defined by interface firmware.
The function of the switches in the right-hand cluster is determined by protocol and the inter-
face program ROM. These switches are discussed later in this chapter.
The following figure
shows the location of the configuration switches.
Always 11
!~SB
-,-'-.-
LSB
o
,Interrupt Select
Level Code
Switches Switches
MSB LSB
7 0
I DODD DODD I ~
Protocol
Configuration
Switches
Switch 0 Only:
Data Link
Async
Interface Configuration Switches
1 This switch should always be set to 1 poisition on HP 98628 Datacomm Interface. If you are using an HP 98691 Programmable Datacomm
Interface, refer to firmware documentation supplied with the interface for the proper switch setting.
7

8 Interface Configuration
When setting the configuration switches, be sure the switch rockers are fully depressed and
properly seated. Switch se'ttings can be changed by using a ball-point pen or a similar pOinted
tool to depress each switch rocker.
Interrupt Level and Select Code
This section discusses the switch settings of the left-hand cluster. The function of each of these
switches, except one,
is determined by interface hardware, and is not protocol dependent.
Remote Switch
The function of the left-most switch (switch 7) is protocol-dependent. If your interface is an HP
98628 (AsynciData Link Protocol), it is reserved for possible future use, and should be in the
OFF (1) position. This ensures proper operation of the card during power-up and self-test
operations. For the
HP 98691 Programmable Datacomm Interface, consult the operating
manuals provided by supplier of the special firmware installed
on your interface.
Interrupt Level
The next two switches define the hardware interrupt level. Levels 1 and 2 are reserved for
internal peripherals only, leaving interrupt levels 3 thru 6 available for interfaces to external
peripherals. Interrupt level 3
is lowest priority; 6 is highest. If an interrupt request conflict
occurs, service
is provided by the computer on the basis of highest priority first. If two devices at
the same level interrupt simultaneously, the interrupts are serviced in the order they are en-
countered by the operating system.
When assigning interrupt levels,
don't forget that some interfaces may require that no other
interface be placed at the same interrupt level (such as the HP 98625 High-speed Disc Interface
used
in Shared Resource Management applications). The factory-default setting of interrupt
level 3
is adequate for most applications. Here is a listing of the available interrupt level settings:
Interrupt Level Switch Settings
Switch Settings
Interrupt
6 5 Level
0 0 3
0 1 4
1 0 5
1 1 6
Interface Select Code
Each internal peripheral and external peripheral interface has a unique interface select code by
which
it is accessed when the operating system must transfer information to or from that device.
The interface select
code is determined by hardware settings, but the interaction can vary,
depending
on the operating system and software being used.

Interface Configuration 9
Select codes 1 thru 6 are reserved for internal peripherals such as the keyboard, disc drives,
CRT display
and other devices. Select code 7 is used by the internal HP-IB interface, leaving
select codes 8 thru 31 available for
other interfaces to external peripherals. However, not all
language options support the entire range of select codes,
and default select codes for certain
devices may vary, depending on the language being used. Refer to the interfacing
or 110
manual for the language being used for more information about restrictions on select code
values.
Some general guidelines apply to select code assignment regardless of which language is being
used. The most important restriction
is that you must never set more than one interface to a
given select
code value. Otherwise, the interfaces compete whenever any information transfer
or control or status operation is performed on that select code. Each interface is marked with a
recommended default setting. This setting is adequate for most languages, but may have to be
altered in some specific instances, especially if one computer is being used for multi-language
applications,
and supports several peripherals.
Note
When assigning a select code other than the one printed on the
interface cover, check the select code assignments for
all other inter-
face cards
in the system. Do not assign the same select code to more
than
one interface.
Here are the available interface select code switch settings. The default setting of 20 is high-
lighted.
Select Code
othru 7
8
9
10
11
12
13
14
15
16
17
18
19
Select Code Settings
:' '.' ,c f' ,
i~/I!'1 :1., I
MSB 43210 LSB
Do not use
01000
01001
01010
01011
01tOO
01101
01110
01111
01100
10001
10010
10011
Select Code MSB 43210 LSB
20 10100
21 10101
22 10110
23 10111
24 11000
25 11001
26 11010
27 11011
28 11100
29 11101
30 11110
31 11111

10 Interface Configuration
Protocol Configuration
During system power-up or reset, the right-hand switch cluster configures protocol-dependent
default operating parameters or functions. On the HP 98628 (Async/Data Link protocol) inter-
face, these switches establish various operating parameters such as handshake protocol and
baud rate. For the HP 98691, refer to the applicable firmware and protocol operating manuals
for the needed information.
This section discusses protocol configuration switch settings for
the Async/Data Link protocol
interface, 98628A Option 100.
Async/Data Link Protocol Selection
The right-most (bit 0) switch in the default cluster selects the power-up default of asynchronous
(Async) or DSN/DL (Data Link) protocol. The function of the remaining 7 switches depends on
which protocol is selected.
Async Protocol Default Configuration
At power-up, the datacomm interface is automatically configured using the default switch
settings. The initial configuration can be altered under program control by the use of CON-
TROL and STATUS statements in BASIC, or their equivalent in other languages. To use the
. default values, omit the corresponding control operations from your program. When Async
protocol is selected 1, the remaining 7 switches have the following functions:
1000000001
Parity
00= None
01 = None
10=Odd
11 = Even
Bits/Char
8
7
7
7
Hardware Handshake
00 = Handshake OFF,
non-modem connection'
01 = IFULL Duplex modem
connection2
10= HALF Duplex modem
connection2
11 =Handshake ON,
non-modem connection'
Async Default Configuration Switches
Baud Rate
000 = 110
001 = 150
010 = 300
011 =600
100= 1200
101 =2400
110= 4800
111 = 9600
Stop Bits
2
2
1
1
1
1 Protocol can also be overridden by CONTROL operations, but the other parameters established by default switches must be replaced by
CONTROL operations in order to ensure proper configuration.

Interface Configuration 11
Before you set up the default switches, determine the proper operating parameters for your
application, then set the parity, hardware handshake,
and baud rate switches as indicated in the
figure. Be sure that
all switches are fully seated in their proper positions to ensure proper
operation.
Character format parameters are determined by the requirements of the device at the other
end
of the datacomm link. Ifdefault switches are used to establish operating parameters, only parity
and baud rate can be selected. Bits per character and stop bits per character are determined by
the parity
and baud rate settings. Default switch settings can be overridden under program
control. Control register operations can
be used to independently program all character format
parameters (for exan1ple, bits per character
and stop bits are not dependent on baud rate or
parity settings). Status register operations can
be used to determine current interface settings.
Values returned represent current operation,
and may not match the current default switch
settings if a previous Control operation has overridden the switches.
For 3-wire
non-modem connections, the hardware handshake is set to handshake OFF, non-
modem connection. If the full complement of handshake signals such as data terminal ready,
clear-to-send, etc. are available
in non-modem connections, then set the switches to hardware
handshake ON,
non-modem connection. If modems are being used, set halflfull duplex to the
appropriate configuration. This completes default switch configuration for Async connections.
Data Link Protocol Default Configuration
As when Async protocol is selected, the datacomm interface is automatically configured at
power-up according to default switch settings. The initial configuration can be altered under
program control by the use of CONTROL and STATUS statements in BASIC, or their equiva-
lent
in other languages. To use the default switch settings, omit the corresponding control
operations from your program. When Data Link protocol
is selected\ the remaining 7 switches
have the following functions:
1000000001
1000000001
DID: ("@" ... "G")
Baud Rate
Hardware Handshake
000 = @i 100= D 00 = 300 00 = Handshake OFF, non-modem connection
001 = A 101 = E 01 = 1200 01 = FULL Duplex modem connection
010 = B 110 = F 10= 9600 10 = HALF Duplex modem connection
011 = C 111 = G 11 =
19200 11 = Handshake ON, non-modem connection
Default GID = "A" Default No Activity timeout: 10 minutes
Data Link Default Configuration Switches
1 Protocol can also be overridd'2n by CONTROL operations. but the other parameters established by default switches must be replaced by
CONTROL operations in order to ensure proper configuration.

12 Interface Configuration
Before you set up the default switches, determine the proper operating parameters for your
application, then set the parity, hardware handshake, and
baud rate switches as indicated in the
figure. Be sure that
all switches are fully seated in their proper positions to ensure reliable
operation.
Interface Installation
After the configuration switches have been set, you are ready to install the interface in the
computer. Most computers that use this interface have
one or more 110 backplane cover plates
that protect the accessory/backplane enclosure. To install the interface, remove the appropriate
cover
and carefully slide the interface into the selected slot, usually the one below the centerline
of the cover plate retainer nuts in the computer or expander frame.
Seat the interface into the
backplane connector, then tighten the two thumbscrews to hold the interface in place. Do not
overtighten. The interface
is now ready to be connected to an interconnecting cable or adapter
between the interface
and whatever data communication equipment you are using in your
application.

13
Chapter 3
Interface Cables
Before the datacomrn interface can interact with a remote computer or other device, it must be
connected to the data communications link. This can be a simple direct connection to a host
computer nearby,
or it can be to a modem or other device that uses a more sophisticated
connection such as a switched telephone network connection or satellite microwave link.
The
type of connection determines what type of cable is needed for a given application. This
chapter explains how to connect cables for various applications,
and includes schematic dia-
grams of the cable options available for the datacomm interface.
RS-232C Connections
There are two types of cables available for RS-232C applications. Both are equipped with
25-pin
EIA connectors designed to mate with connectors on other RS-232C devices or equip-
ment.
• The Option 001 (DTE) cable has a male connector, and is designed for connecting the
interface to an RS-232C-compatible modem or other data communications equipment.
The DTE deSignation means the cable
is designed to be used as a Data Terminal EqUip-
ment (DTE) interconnect to Data Communications EqUipment (DCE).
• The Option 002 (DCE) cable has a female connector and is internally cross-wired so that
the datacomm interface acts like DCE, such as a modem. Thus, by using two cables,
one
of each type, two computers can be connected directly to each other, back-to-back,
without using
modems or other devices between the two.
Optional Drivers and Receivers
Two optional drivers and receivers are used with the RS-232C cable optionsl. Their functions
are as follows:
Drivers
Name Function
OCDI
OCD2
OCD3
OCD4
Data Rate Select
Secondary Request to
Send
Not used
Not used
Receivers
Name Function
OCRI
OCR2 Ring Indicator
Secondary Data Carrier Detect
OCD2 is used for auto-dial pulsing in the HP 13265A Modem. None of the optional drivers and
receivers are used fc)r Data Link and Current Loop adapters.
1 These driver and receiver assignments are for the HP 98628 Datacomm Interface, and may not apply to the HP 98691 Programmable
Datacomm Interface. Refer to documentation from the firmware supplier for that information.

14 Interface Cables
Option 001 DIE (Male) Cable
The male DTE cable (5061-4215) is compatible with most RS-232C modems. It is designed so
that you can connect a modem directly to the datacomm interface without using an intermedi-
ate adapter.
The following cable schematic shows which drivers
and receivers are connected to respective
pins
in the male RS-232C connector. It also includes the test connector schematic showing the
loop-back signal paths used for testing the interface
and cable.
98628 5061-4215 RS-232C
INTERFACE OTE CABLE SIGNALS
~(12 ) BA(PIN2)J
~
~f-(4=2,---- __ ~) BB (PIN 3)
~
~f-(=13 ___ ~) CA (PIN 4)
~(44 ) CB(PIN 5)
~*""(4_6 ___ ~) CF (PIN 8)
~*""(_15 ___ ~) SCA(PIN 19) J
~
~(47 ) SCF(PIN 12)
~
~f-(.;....;14 ___ ~) CD(PIN 20)~ __
~f-(9~ __ ~) CE (PIN 22) r--+-'
~f-(4..;..;:5~ __ ~) CC(PIN 6) ~~
~41 ()
~( ) DB PIN 15 >-- __
~43 )
~f-(~--~) DD(PIN 17
SIGNAL ~f-(48~ __ ~) AB (PIN 7) >-
GROUND~
SAFETY '---<f-(2;;;;..;4~ __ ~) AA (PIN I) >-
GROUND... .
~7
~f-( "'-----~) DA (PIN 24)
~f-(4..;..;:O~ __ ~) CH (PIN 23) >----'
t t t
INTERFACE MALE (1251-6625)
REAR PANEL RS-232C FEMALE
CONNECTOR CONNECTOR RS-232C TEST
CONNECTOR
Option 001 DTE Interface Cable and Test Connector