
Q232-STS
RS-232 Serial Transfer Switch User Manual
095-160140-1000, Rev. A00 © QuEST Rail LLC 2018 1
User Manual
Overview
The QuEST Q232 Serial Transfer Switch transfers RS-
232 signals from a primary communications link to a
backup communications link. Designed for railway
applications, the Q232-STS meets the demanding
environmental requirements of Class C wayside
signal equipment.
The Q232-STS is packaged in a low-profile rugged
plastic case with ears for wall mounting.
Power is connected to a two-wire removable plug
connector. The serial data connectors are DB9 male
for the primary and backup links and DB9 female for
the interlocking controller connection.
The Q232-STS will transfer to the backup link when
the backup communications equipment asserts its
DCD signal and transmits data. When the backup
link de-asserts its DCD signal, the Q232-STS will
switch back to the primary link.
Product Features
• 10 – 32 VDC Input Voltage Range
• 2,000 Vrms isolation
• -40 to 70° C Operating Range
• Supports data rates up to 57,600 bps
• Transfers from primary to backup link when
Backup DCD and RXD signals are active
• Status and data activity LEDs
Specifications
Serial Ports
Primary Port DB9 M (RXD, TXD, RTS, DCD, and
COM)
Backup Port DB9 M (RXD, TXD, RTS, DCD, and
COM)
Controller Port DB9 F (RXD, TXD, RTS, CTS, DCD,
and COM) CTS connected to RTS
Data Rate Up to 57,600 bps
Isolation 2,000 Vrms (60 Hz, 3 mA maximum
leakage for 60 s)
Note: No isolation between primary
and backup ports.
Power Input
Power Connector 2-position removable terminal block
Wire Size 22 to 14 AWG
Input Voltage 10 to 32 VDC
Power Consumption 0.7 W (12 VDC), 1.9 W (32 VDC)
Fuse 2 A
Reverse Polarity
Protection
Yes
Indicators
Power Green LED
RS-232 Signals Yellow LEDs
Link Active Blue LEDs
Mechanical
Dimensions 7.285 x 4.72 x 1.25 in.
Case Material Flame retardant ABS
Environmental (AREMA Class C Compliant)
Operating Temperature -40 to 70° C
Operating Humidity 0 to 95% non-condensing
Ordering Information
PN: 800-160140-0001
Email PO to: orders@questrail.com