User manual
Table Of Contents
- Chapter 1 Introduction
- Chapter 2 Hardware Configuration
- 2.1 Initial Inspection
- 2.2 Jumper and Switch Locations
- Figure 2.1: PCI-1601A/B Silk Screen
- Figure 2.2: PCI-1601AU/BU Silk Screen
- Figure 2.3: PCI-1602A/B Silk Screen
- Figure 2.4: PCI-1602AU/BU Silk Screen
- Figure 2.5: PCI-1602UP Silk Screen
- Figure 2.6: PCI-1603 Silk Screen
- Figure 2.7: PCI-1604UP Silk Screen
- Figure 2.8: PCI-1610A/B Silk Screen
- Figure 2.9: PCI-1610CU Silk Screen
- Figure 2.10: PCI-1610AUP/UP Silk Screen
- Figure 2.11: PCI-1610AJP Silk Screen
- Figure 2.12: PCI-1611U Silk Screen
- Figure 2.13: PCI-1612A/B Silk Screen
- Figure 2.14: PCI-1612AU/U Silk Screen
- Figure 2.15: PCI-1612CU Silk Screen
- Figure 2.16: PCI-1620A/B Silk Screen
- Figure 2.17: PCI-1620AU/U Silk Screen
- Figure 2.18: PCI-1622CU Silk Screen
- 2.3 Jumper Settings
- 2.3.1 How to Set Jumpers
- 2.3.2 Default Settings
- 2.3.3 Mode Selection by Jumper/DIP Settings
- Figure 2.21: PCI-1612 Series RS-232/422/485 Selection
- Figure 2.22: RS-422/485 Selection by Jumper Setting
- Figure 2.23: PCI-1603 RS-232 Mode Jumper Setting
- Figure 2.24: PCI-1603 Current-loop Mode Jumper Setting
- Figure 2.25: Active Mode Jumper Setting
- Figure 2.26: Passive Mode Jumper Setting
- Figure 2.27: Resistor Selection
- 2.4 Card Installation
- Chapter 3 Driver Setup & Installation
- Chapter 4 ICOM Tools
- Chapter 5 Pin Assignments and Wiring
95 Chapter 5
5.2.3 RS-485 Signal Wiring
The RS-485 standard supports half-duplex communication. This means
that just two wires are needed to both transmit and receive data. Hand-
shaking signals (such as RTS, Request To Send) are normally used to
control the direction of the data flow and to switch the transmission
accordingly. In RS-485 mode, the PCI-1601/1602/1611/1612/1622 cards
automatically sense the direction of the data flow and switch the trans-
mission direction — no handshaking is necessary. This means a user can
build an RS-485 network with just two wires. This RS-485 control is
completely transparent to the user. The software written for half duplex
RS-232 works without any modification.
Figure 5.2: RS-485 Wiring Topology
Termination Resistor Setup
You can install termination resistors if necessary for impedance match-
ing. The card has mounting spaces for termination resistors, but no resis-
tors are installed at the factory. Depending on your application you may
need to solder in a single resistor to handle the DATA+/DATA- pair (and
a corresponding resistor on the other end of the connection). The
value of the resistor should equal the characteristic impedance of the sig-
nal wires (approximately 120 Ohms or 300 Ohms).