WTI CAS-81 User manual

WTI Part Number: 12365
Rev. C
CAS-81
8-PortCodeActivatedSwitch
User's Guide
5 Sterling ·Irvine ·California 92618
[phone] ·Toll Free: 1-800-854-7226
Fax: [phone] ·http://www.wti.com

Table of Contents
1. Introduction.............................................1-1
2. Unit Description ..........................................2-1
2.1. Front Panel Indicators ....................................2-1
2.2. Back Panel ..........................................2-2
3. Installation .............................................3-1
3.1. Set DIP Switches .......................................3-1
3.1.1. Data Rate (Baud) Selection (Switches 1 through 3) ..............3-1
3.1.2. Timeout Selection (Switches 4 and 5) ......................3-1
3.1.3. Quiet Mode (Switch 6)...............................3-1
3.1.4. Auto Con nect Se rial Port 1 (Switch 7)......................3-2
3.1.5. Broadcast Mode (Switch 8) ............................3-2
3.1.6. Force CTS (Switch 9) ...............................3-2
3.1.7. Force DCD (Switch 10) ..............................3-2
3.2. Connect Power Cable ....................................3-3
3.3. Connect DevicestoSe rialPorts ..............................3-3
3.4. Connect Control Port.....................................3-3
3.5. RS422 Line Driver Option .................................3-3
4. Operation ..............................................4-1
4.1. Power Up ...........................................4-1
4.2. ASCII Characters.......................................4-1
4.3. Com mand String .......................................4-1
4.4. CommandResponse .....................................4-2
4.5. Port Gating ..........................................4-2
4.5.1. Open Port Gating ..................................4-2
4.5.2. Close Port Gating..................................4-2
Appendices
A. Description of System Interfaces ..............................Apx-1
A.1. Control Port (DB25 Female) ..............................Apx-1
A.2. Se rial Ports 1 through 8 (DB9 Male) ..........................Apx-2
A.2.1. RS422 Line Driver Op tion ...........................Apx-2
B. Specifications ..........................................Apx-3
C. FCCNotice............................................Apx-3
D. Customer Service ........................................Apx-4
List of Figures
2.1. Front Panel Indicators ......................................2-1
2.2. Back Panel .............................................2-2
A.1. Control Port / Serial Port Interface .............................Apx-1
A.2. RS422 Option Interface....................................Apx-2
2

1. Introduction
The CAS-81 Code Activated Switch brings the convenience of code-based RS232 switching to
sites with multiple terminals, printers, and peripherals. The CAS-81 enables a single RS232
Control Port to switch between 8 devices via an ASCII code sequence.
Code based switching lets you control the CAS-81 from your PC or mainframe. When a
modem is attached to the Control Port, the CAS-81 can also be managed from a remote
location. Devices can be connected or disconnected by sending commands from a remote PC
via modem.
The CAS-81 can operate at speeds up to 115,000 bps and passes data in "real-time" with no
delays. Binary and graphics files can be safely passed due to the unique 8 character switch
instruction, which considerably reduces the chances of false switching.
A broadcast mode makes it easy to mass-address a group of printers, display devices, or an
array of laboratory instruments by directing the data on the Control Port to all Serial Ports
simultaneously. The broadcast mode may be selected by code or permanently selected by the
Select Switch.
An Auto-connect feature allows the Control Port to automatically connect to Serial Port 1 each
time the unit is powered up, or after a timeout or disconnect. This provides a data path to a
critical device in case of a power failure, or convenient connection to commonly used
equipment.
Each Serial Port may be configured for a balanced RS422 long distance line driver by simply
removing the socketed RS232 driver chip and plugging in an optional RS422 module. When
the module is installed, an LED on the back panel indicates the port is RS422.
Applications
·Industrial Robotic and Numeric Control
·Remote Diagnostics
·Laboratory Equipment Polling
·Data Acquisition
·Network Management
Typographic Conventions
Throughout the manual, typefaces and characters have been used to denote the following:
^(e.g. ^X)Indicates a key combination that is used to invoke a command.
For example, the text "^X" (Control X) indicates that the [Ctrl] key and
the [X] key should be pressed simultaneously.
COURIER FONT Indicates characters typed on the keyboard.
For example, ^VS or ^C#.
1-1

2. Unit Description
2.1. Front Panel Indicators
ÀON: Indicates power to the unit is ON.
ÁRDY: Indicates unit is Ready to operate. A steady blink indicates that the CAS-81 is
operating normally.
ÂTXD: Indicates that data is being received at Control Port pin 2.
ÃRXD: Indicates that data is being transmitted out Control Port pin 3. Also indicates that
data is being received by pin 2 of a selected Serial Port.
ÄRTS: Indicates that the "Request to Send" signal is present at Control Port pin 4.
ÅCTS: Indicates that the "Clear to Send" signal is present at Control Port pin 5. Also
indicates that the "Clear to Send" signal is present at pin 8 of a connected Serial Port.
Always high when all ports are disconnected.
ÆDTR: Indicates that the "Data Terminal Ready" signal is present at Control Port pin 20.
ÇDCD: Indicates that the "Data Carrier Detect" signal is present at Control Port pin 8.
Also indicates that the "Data Carrier Detect" signal is present at pin 1 of a connected
Serial Port. Always high when all ports are disconnected.
ÈSerial Ports 1 - 8: Indicates that the corresponding numbered Serial Port is currently
connected.
2-1
Figure 2.1: Front Panel Indicators

2.2. Back Panel
ÀSerial Ports 1 - 8: Eight RS232 DB9 male connectors configured as DTE. Accepts a
standard AT 9 pin to printer or modem cable, depending on the application. Refer to
Appendix A for more information on the Serial Port Interface.
Note that when the RS422 Line Driver Option has been installed, an LED indicator will
be present in the blank above the Serial Port. This LED indicates that the port is
configured for RS422 communication.
ÁControl Port: RS232 DB25 female connector configured for DCE. Accepts a standard
PC to Modem Cable.
The CAS-81 will respond to proper ASCII code strings received by the Control Port.
Once a port is selected, data will pass between the Control Port and the selected Serial
Port. Refer to Appendix A for more information on the Control Port interface.
ÂDefault Switch: An 8 position DIP switch that is used to select the Control Port Data
Rate, No-data timeout period, and the Auto connect and broadcast features. This switch
is read upon power up.
ÃAC Power: Standard AC power cord receptacle and ON/OFF switch.
2-2
CAS-81 Code Activated Switch, User's Guide Unit Description
Figure 2.2: Back Panel