Camden Door Controls CV-940-SER Installation Instructions

1.0 General Description

The CV-940-SER Series is a 2 channel non-powered RS232
to RS485 interface converter.CV-940-SER can convert the
TD and RD signals of RS232 into balanced half-duplex
RS485 signals.

CV-940-SER Series

Installation Instructions

2.0 Specifications

2.1 Interface

Conforms to EIA RS232 and RS485 standards

2.2 Connectors and signals

The CV-940-SER has a DB-9 female connector on the RS232
side and DB-9 male connector or a terminal block connector
on the RS485 side.

RS232 Side:

Connector: DB-9 Female.

Signals: Use Pins 3 (RD) and Pin 2(TD also called SD).

Pins 7 (RTS) and 8 (CTS) are tied together. Pins 4 (DTR),
6 (DSR), and 1 (CD) are tied together.

RS485 Side:

Connector: DB-9 male connector or 4 position terminal

block -485+.485-.+5V.GND .

2.3 Data Rate

300 to 115.2 KBPS, up to 4,000 feet at 19,200 BPS.

2.4 Sending Control

CV-940-SER does not need RTS to control the RS485 driver.

The RS485 driver is automatically enabled during each
spacing state of the SD line (also called TD) on the
RS232 side.

The CV-940-SER has an internal connection to prevent data
transmitted from the RS232 port from being echoed back to
the RS232 port. The CV-940-SER is used as a two wire
(half duplex) RS485 Converter.

2.5 Operating Distance

Data Rate

(KBPS)

Max. Distance

(feet)

Max. Distance

(meters)

using 24 AWG wire

19.2 9.6 4.8 2.4

4,000 6,000 8,000 10,000

1,219 1,828 2,438 3,048

2.6 Power

CV-940-SER is powered from the RS232 data TD or
hand-shake lines.

It will try to get its power from RTS or DTR (at least +5.5V or -5.5V
in the quiescent state). If there are no RS232 control signals
(DTR or RTS) available, CV-940-SER will get power from the data

input TD pin (at least -5.5V in the quiescent state). Sufcient

power is needed to operate the device. In some cases there may
not be any available and the TD can not drive the CV-940-SER.
An external 5VDC/40mA power supply can be connected to two
terminals on the RS485 connector marked +5VDC and GND.

2.7 Dimensions

3.5” x 1.3” x 0.7” (88 mm x 33 mm x 17mm)

2.8 Environment

32° to 122°F (0° to 50°C), 5% to 95% Relative humidity

3.0 CV-940-SER connecting other RS485 device

CV-940-SER DB-9 Male

PIN2(485-) 485-

PIN7(485+) 485+

Push Buttons Keypads Strikes Magnetic Locks Key Switches Relays & Timers Access Control

5502 Timberlea Blvd.,
Mississauga, ON Canada
L4W 2T7

www.camdencontrols.com
Toll Free: 1.877.226.3369

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File: CCV-940-SER Series
Installation Instructions.indd R1
Revision: 26/08/2015
Part No.: 40-82B181