WTI CAS-161A User manual

WTI Part No. 12114
Rev. D
CAS-161A
Code Activated Switch
User’s Guide

Table of Contents
1. Introduction ...........................................1-1
2. Unit Description ........................................2-1
2.1. Front Panel Indicators..................................2-1
2.2. Back Panel Components ................................2-2
3. Installation ............................................3-1
3.1. Configure SetUp Switches ..............................3-1
3.1.1. SetUp Switch Bank 1 ...........................3-1
3.1.1.1. Prefix Code Repetition
Value (Sw1 - Sw4) ....................3-1
3.1.1.2. Broadcast Mode (Sw5) ................3-2
3.1.1.3. Baud Rate Select (Sw6 - Sw8) ..........3-2
3.1.2. SetUp Switch Bank 2 ...........................3-2
3.1.2.1. Prefix Code (Sw1 - Sw7) ..............3-2
3.1.2.2. Parity (Sw8) .........................3-4
3.2. Connect Power Cable ..................................3-4
3.3. Connect Data Cables...................................3-4
4. Port Selection ..........................................4-1
4.1. Selecting a Port .......................................4-1
4.2. Closing/Opening All Ports..............................4-2
Appendices
A. Interface Description .................................Apx-1
A.1. RS232 Ports (Standard)..............................Apx-1
A.2. RS422 Ports (Optional) ..............................Apx-1
B. Printable Prefix Codes................................Apx-2
C. Installing Add-On Modules ...........................Apx-3
D. Specifications ........................................Apx-5
E. Customer Service ....................................Apx-6
F. FCC Statement.......................................Apx-7
i

List of Figures
2.1. Instrument Front Panel......................................2-1
2.2. Instrument Back Panel ......................................2-2
A.1. RS232 Interface .........................................Apx-1
A.2. RS422 Interface .........................................Apx-1
C.1. Add-On Module Installation ..............................Apx-3
ii
Table of Contents

1. Introduction
The CAS-161A Code Activated Switch enables a single RS232
Control port to switch between 16 to 64 ports via an ASCII code
sequence.
The code sequence is a user-selectable Prefix code and a Port
Select code. The Prefix code is set via the Setup switch on the
bottom of the unit. For added security, the Setup switch can be
set to require one, two, four or eight of the same Prefix codes.
The Port Select code selects the desired port and allows data to
pass between it and the Control port until the next Prefix/Port
Select code is detected.
The CAS-161A also features a Broadcast mode which enables the
Control port to transmit to all ports.
Optional RS422 line drivers can be factory installed to increase
data transmission up to one mile.
The CAS-161A is field-expandable to 32, 48 or 64 ports by
attaching up to three additional Add-On Modules to the master
unit. CAS-161A applications include:
·Industrial Robotic and Numeric Control
·Remote Diagnostics
·Quality Control for Test Environment
·Laboratory Equipment Polling
·Electronic Rotary Switch Selection for Data Gathering
·Data Acquisition
1-1

Typographic Conventions
Throughout this User's Guide, typefaces and characters have
been used to denote the following:
[Key] Text set in bold face and enclosed in
square brackets indicates a specific key.
For example [Enter] or [Esc].
^(e.g. ^V) Indicates a key combination used to invoke
a command. For example, the text “^V”
(Control V) indicates the [Ctrl] key and
the [V] key must be pressed
simultaneously.
COURIER FONT Indicates characters typed on the keyboard.
For example ^Yk or ^V
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CAS-161A User’s Guide

2. Unit Description
2.1. Front Panel Indicators
ÀPWR: (Power) Indicates power to the unit is ON.
ÁTXD: (Transmit Data) Indicates data is being transmitted
out pin 2 of the Control port (MODEM Port). Indicates
data is being received at pin 2 of the selected port.
ÂRXD: (Receive Data) Indicates data is being received at
pin 3 of the Control port.
ÃRTS: (Request to Send) Indicates high RS232 signal at
pin 4 (output) of the Control port. Indicates high signal at
pin 4 (input) of the selected port.
ÄCTS: (Clear to Send) Indicates a high RS232 signal
received at pin 5 (input) of the Control port.
ÅALL: Indicates Broadcast Mode is active, all ports open.
ÆSECTION Indicators: When optional Add-On Module(s)
are present, indicators show port connections on master or
Add-On Modules as follows:
·Section 1: Ports1-16selected on master unit.
·Section 2: If second Module is present, indicates Ports
17 - 32 selected.
·Section 3: If third Module is present, indicates Ports
33 - 48 selected.
·Section 4: If fourth Module is present, indicates Ports
49 - 64 selected.
Example: If Section 4 LED and Active Port 2 LED are lit,
this indicates port 50 is selected (2 + 48 = 50).
2-1
Figure 2.1: Instrument Front Panel

ÅACTIVE PORT Indicators: These indicators are used
with the previously mentioned SECTION LEDs to indicate
the port currently connected to the Control port.
2.2. Back Panel Components
ÀInput Ports1-16: Ports labeled1-16are25-pin,
female, RS232 connectors. Optional RS422 connectors can
be factory installed to increase data transmission distance.
For a description of the port interface, please refer to
Appendix A.
ÁMODEM Port (Control Port): A 25-pin, female, RS232
connector. For a description of the port interface, please
refer to Appendix A.
ÂAC Power: Power connector and ON/OFF switch. The
unit can be jumper-selected for either 115 or 230 VAC.
ÃSetUp Switches: (Not Shown) Two banks of DIP switches
located on the underside of the unit. The SetUp Switches
are used to configure the prefix code, select baud rates and
parity, and set other features as described in Section 3.
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CAS-161A User’s Guide
Figure 2.2: Instrument Back Panel

3. Installation
3.1. Configure SetUp Switches
There are two banks of DIP switches located on the bottom of the
CAS-161A unit. These switches are used to configure the Prefix
Code (command character), enable the Broadcast Mode, and
select the baud rate. Switch functions are summarized on the
bottom of the unit and in the sections that follow:
Note: Switch positions “1” and “0” are indicated on
the bottom of the unit.
3.1.1. SetUp Switch Bank 1
The bank of switches located closest to the rear panel are used to
select the Prefix Code Repetition Value, Broadcast Mode, and
baud rate.
3.1.1.1. Prefix Code Repetition Value (Sw1 - Sw4)
The Prefix Code informs the unit that the next character will be a
command. In order to allow the unit to adapt to a variety of
applications, it is often useful to require that the Prefix Code be
repeated several times in order to be recognized. For example if
the Prefix Code is ^V and the Repetition Value is 4, then the
sequence “^V^V^V^V” would be sent prior to a port selection
command.
Note: When transmitting binary data, it is
recommended that the Repetition Value be set at four
or eight. This will decrease the possibility of random
characters in data being misinterpreted as commands.
Prefix Code Repetition
Switch (Bank 1)
1234
1 x Prefix Code * 1000
2 x Prefix Code 0100
4 x Prefix Code 0010
8 x Prefix Code 0001
* = Factory Setting
3-1

3.1.1.2. Broadcast Mode (Sw5)
On (1) forces all ports open. Data from the Control (MODEM)
port is sent to all Input ports. Useful for broadcasting to or
controlling all Input devices. When enabled, concurrent data
sent by Input ports to the Control port will be jumbled together.
Broadcast Mode Sw5
Disable* 0
Enable 1
* = Factory Setting
3.1.1.3. Baud Rate Select (Sw6 - Sw8)
Selects the operating baud rate; from 150 to 19.2K baud.
Baud Rate
Switch (Bank 1)
678
19200 0 0 0
9600* 1 0 0
4800 0 1 0
2400 1 1 0
1200 0 0 1
600 1 0 1
300 0 1 1
150 1 1 1
* = Factory Setting
3.1.2. SetUp Switch Bank 2
The bank of DIP switches located closest to the front panel are
used to select the Prefix Code character and set the parity.
3.1.2.1. Prefix Code (Sw1 - Sw7)
As mentioned previously, the Prefix Code informs the unit that
the next character will be a command. The Prefix code can be
any ASCII character. However, since it is passed on to the
connected device, it is recommended to use a non-printable
character. The factory default is ^V (Control V). Please refer to
the following table when selecting a Prefix Code.
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CAS-161A User’s Guide