BB-USR604
18
The following illustration shows the pin numbering of the DB-9M connector.
Figure 12: DB-9F Pin Numbering
The following table shows the wiring pin-outs for RS-232, RS-422 and RS-485 two-wire and four-wire connections.
Pins
RS-232 (DTE)
RS-422/RS-485 (4-wire)
RS-485 (2-wire)
1
Data Carrier Detect (DCD)
RDA(-)
---
2
Receive Data (RD)
RDB(+)
---
3
Transmit Data (TD)
TDB(+)
DATA B(+)
4
Data Terminal Ready (DTR)
TDA(-)
DATA A(-)
5
Signal Ground (GND)
GND
GND
6
Data Set Ready (DSR)
---
---
7
Request To Send (RTS)
---
---
8
Clear To Send (CTS)
---
---
9
Not Used
---
---
TERMINATION AND BIASING
The BB-USR604 converter includes internal biasing resistors on the RS-422/RS-485 interfaces.
The values for internal biasing resistors are:
Biasing: 1k Ohms (default IN PLACE when in RS-422/485 modes)
The biasing resistors are connected to the receive lines, pulling the RDA(-) line to ground and the RDB(+) line to a
positive voltage. The bias resistor is automatically IN when you select RS-422/485 mode.
For additional information on termination and biasing download the RS-442 and RS-485 Applications eBook from
www.advantech.com
or contact Technical Support at Advantech B+B SmartWorx: 1 (815) 433-5100 (Central Time-
USA)
Summary of Contents for BB-USR604
Page 1: ...MODEL BB USR604 4 PORT USB ISOLATED SERIAL CONVERTER USER MANUAL ...
Page 28: ...BB USR604 31 BB USR604 DIMENSIONS Figure 18 BB USR604 Dimensional Diagram ...
Page 29: ...BB USR604 32 PANEL MOUNT DIMENSIONS Figure 195 BB USR604 Panel Mount Dimensions ...
Page 33: ...BB USR604 36 SERIAL PORT WIRING RS 232 CONNECTIONS Figure 25 USR602 RS 232 Connections ...
Page 34: ...BB USR604 37 RS 485 TWO WIRE CONNECTIONS Figure 26 USR602 RS 485 Two Wire Connections ...