3.0 INSTALLATION
The Model 3/9 HDX requires no configuration prior to, or
subsequent to, installation: It is strictly "plug and play". This section
tells how to install the Model 3/9 HDX in a half-duplex application.
3.1 CONNECTING THE INTERFACE PORTS
Model 3/9 HDX is designed to plug directly between DTE and DCE
devices with a monitoring device connected to the DB-9 “Tap”
connector.
In a typical data acquisition (DAQ) or process control half-duplex*
application, (see Figure 1, below) only one device communicates on the
data bus at a time. By connecting a monitor to the “Tap” side of Model
3/9 HDX, you can independently monitor both directions (TD and RD -
pins 3 and 2, respectively) of the data bus without interrupting data flow.
*NOTE: Model 3/9 HDX will not work in full-duplex applications.
Follow the instructions below to make install the 3/9 HDX.
1. Disconnect the cable from the master device. Verify all DB-9
pin connections. NOTE: Pins 3 and 2 are connected through
an OR gate to the tap connector. All other pins are wired
straight-through (See Appendix B for Pin Assignments).
2.
Connect the master device into the “A” port of Model 3/9 HDX.
3. Connect the bus cable into the “B” port of Model 3/9 HDX.
4. Connect the monitoring equipment to the DB-9 tap connector.
5. Resume operations while monitoring data and control signal
activity.
3
4
Figure 1. Typical Application of Model 3/9 HDX in Half Duplex Environment
APPENDIX A
SPECIFICATIONS
Data Rates: Up to 115,200 bps
Transmission Format: Asynchronous or synchronous
Transmission Mode: Half duplex
Interface: EIA-574
Connectors: DB9 Male or Female on all ports (All Configurations
Available: MF-F, MF-M, MM-F, MM-M, FF-F, FF-M
Power: Derived from RS-232 data and control signals, no AC power or
batteries required
Temperature Range: 0-50
°
C (32-122
°
F)
Humidity: Up to 95% non-condensing
Host
Computer
Model 3-9 HDX
Monitor
DAQ Equipment
