COM320 Voice Phone Modem
Voice Synthesizer
Make your datalogger speech-capable
weather applications supported water applications supported energy applications supported gas flux & turbulence applications supported infrastructure applications supported soil applications supported


The COM320 is a voice-synthesizer modem that adds speech capability to a CR800, CR850, CR1000, or CR3000 data logger. This capability allows the user to call a site for a spoken summary of real-time or historical data. The COM320 can also act as a standard modem.

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Benefits and Features

  • Allows anyone to call a COM320-equipped site from any phone (including cellular) to receive a verbal report of current site conditions.
  • Enables the data logger to call you and recite a verbal warning if specified conditions occur.
  • Reports specific conditions or allows selection of information by pressing numbers on a touch-tone telephone
  • Uses voice strings created with CRBasic code
  • Operates over a wide temperature range
  • Supports communication rates up to 115.2 kbps between modem and data logger
  • Includes a speaker that aids troubleshooting in the field


Technical Description

The COM320 has a CS I/O port, power terminals, screw terminals, and an RJ-11C jack. The datalogger connects with the CS I/O port via an SC12 or SC12R-6 cable. The RJ-11C jack is for attaching a surge-protected telephone line. Alternatively, the screw terminals (GND, RING, TIP) can be used to connect the COM320 with a phone line via a surge protector.

The COM320 has a standard word list (see document at right). Campbell Scientific may eventually add more words to the standard list. Customer-requested words for specific applications can also be included; consult the factory for details. The COM320’s sentences are programmed using CRBasic code.

Required Equipment

More detailed information about the required equipment is included under the Configuration tab.

  • Phone
  • Analog phone line
  • Surge protector at the datalogger site if one is not installed by the phone company.
  • COM320 voice-synthesizer modem (includes SC12 cable)
  • CR800, CR850, CR1000, or CR3000 datalogger
  • Environmental enclosure
  • Power supply

Datalogger-to-computer communication also requires, at the computer site, a PC or laptop running PC400, LoggerNet, or RTDAQ datalogger support soft ware, 7026 serial cable or equivalent modem cable, and a user-supplied Hayes-compatible modem.


Transmission Distance or Area Worldwide
Operation 1200 to 115200 baud digital communications over phone lines
  • Generated voice messaging for incoming or outgoing calling
  • Touch-tone selection voice responses
Operating Temperature Range -25° to +50°C (standard)
Operating Voltage 12 Vdc
Current Drain
  • ~100 μA (quiescent)
  • ~35 mA (active)
Communication Rate 9600, 38400, 57600, 115200 bps (between data logger and COM320, and selected by user)
Data Logger Interface CS I/O, SDC9 (not changeable)
Standards V.92, K56Flex, V.90, V.34, V.32bis, V32, V23, V22bis, V22, V.21, B212, B103
  • FCC US 3A4M508BSM2-T-W
  • IC 2377 A-SM2TW
  • TBR21
Service Requirements If not available at the site, phone lines must be installed.
Dimensions 16.5 x 2.5 x 6.6 cm (6.5 x 1.0 x 2.6 in.)
Weight 0.16 kg (0.35 lb)


Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.


Product Compatible Note
CR1000 (retired) OS version 16 or higher
CR200X (retired)
CR211X (retired)
CR216X (retired)
CR3000 (retired) OS version 9 or higher
CR5000 (retired)
CR800 OS version 7 or higher
CR850 OS version 7 or higher
CR9000X (retired)

Mounting Equipment

Product Compatible Note


Product Compatible Note

Additional Compatibility Information


The COM320’s “sentences” are programmed using CRBasic code, which is included in PC400 and LoggerNet software. Both of these software packages support automated error-checking or user-initiated contacts.

Phone, Phone Lines, and Surge Protection

The COM320 must connect to an analog phone line. Some office environment PBX phone lines are digital and don’t interface to this analog modem. Of course, any phone may be used to call in to or receive callbacks from the COM320. A touch-tone phone is necessary for input or to navigate through the COM320’s menu system.

Typically, a length of phone line is run from the telephone company's junction box to the COM320s surge protector, and then to the Ground, Tip, and Ring terminals on the COM320. Alternately, if adequate surge protection is provided by the telephone company and the junction box supports it, a length of telephone wire with RJ11C connectors (#2365) can be run directly from the junction box to the socket on the COM320.

If the local telephone company does not provide surge protection, either the 6362 or 4330 surge protector should be used. See "Ordering Info" tab for more information.

Enclosure Considerations

The COM320 requires a desiccated, non-condensing environment; a Campbell Scientific enclosure is recommended. Grommets and screws are provided to attach the COM320 to the backplate of our enclosures.


COM320 Firmware v.4.0 (621 KB) 28-01-2010

Execution of this download installs the COM320 Operating System on your computer.  

Note: The Device Configuration Utility is used to upload the included operating system to the datalogger.  Requires a USB cable.

COM320 USB Driver () 01-01-2014

Windows USB driver for the COM320 are distributed with the Device Configuration Utililty. In the Device Configuration Utility, click on the link "install the device driver for the COM320" in the main body of text for the COM320.

Note: Device Configuration Utility 2.08 or newer is required to install drives and configure the COM320.


COM310 Examples (5 KB) 22-04-2008

CR1000 CRBasic program examples showing COM310 data callback and voice support.

Related FAQs

Number of FAQs related to COM320: 2

  1. No. Any communications device can be used to call out by the newer dataloggers (except the CR200X-series), but the type of communications device used determines what type of information can be sent. The COM320 can be used to call out with a voice or to send data to LoggerNet

  2. Yes. By configuring the NL120 as a CSDC device, both the NL120 and COM320 can share the same CS I/O port. The CR1000 and CR3000 are capable of multi-threading, so the NL120 and COM320 can run in parallel. For more information, refer to the NL120 Ethernet Module Instruction Manual.

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