External Serial PC Watchdog Timer Image External Serial OS Watchdog Timer Image

External Serial PC Watchdog Timer Description

This device is used outside of a PC or other type of computer and monitors for hardware/software lock-ups. It is typically used to cycle AC power (with a power module) on the computer to initiate a restart or reboot. It also has a dry conact relay output available for other timing options.

It provides a solution to reboot PC file servers, telecom, security, kiosk, video surveillance, digital signage and industrial systems that occasionally lock up but must be available on a continuous basis. Increase your system availabilty and protect against unexpected downtime or blue screens (BSOD).

The Serial PC Watchdog timer ships with utility programs for control & "tickling" of the board. Sample source code and libraries are also provided in Visual "C" and Visual Basic to allow users to write their own applications to configure or "tickle" the board. Use the CD image download below to see the samples provided along with all the programmer's documentation. The Serial PC Watchdog works with Win 2K XP Vista Win7 Win 8 Server2003 Server2008  (32 & 64 Bit Versions on all). It also has LINUX support.

The External Serial device has been upgraded so it now supports temperature sensing, non-volatile memory for device configuration, and faster Baud rates. It can now support features similar to the ones found in the USB or PCI PC Watchdog.

This device has been tested with USB to Serial devices based on the FTDI & Prolific chips. It should work fine with other versions also. The board does ship with a 6 foot DB-9M to DB-9F cable.


  • Acts as a pass-through serial port with standard PC DB-9 connectors. Allows you to keep a MODEM or other serial device connected.
  • Monitors the PC serial port for control line activity (TxD, DTR, & RTS) from the PC.
  • Monitors the Ring Indicator (RI) line from a MODEM on the serial port for excessive rings without an answer.
  • Can be used right from the box without any support programs if you already have constant serial port activity.
  • Time-out delays available from 5 seconds to 2 hours
  • Also has a Command Mode that allows a user program to exert additional control over the PC Watchdog.
  • Two externally visible LEDs show status of PC Watchdog.
  • PC Watchdog has I/O port to control an external power module to cycle AC power on a PC and/or external device.
  • Programmable power-on delay to allow the PC to complete its initialization sequence.
  • Non-Volatile memory to store operating parameters.
  • Eight bytes of non-volatile memory reserved for user data to implement simple software protection.
  • Has an on-board temp sensor to detect over-temp conditions.
  • New firmware option allows the Reset (timeout) relay to be reconfigured to act like the Aux relay on the USB board.
  • Option to use power module jack to control an external opto-coupler control at timeout.

The Internal and External Serial PC Watchdogs now have full Windows DLL support with the new Universal DLL released in April of 2010. They are also fully supported with the included Config and Tickle programs for all versions of Windows that support Net Framework 2.0 and higher.

Pricing & Purchase Link

This item can be purchased at the Berkshire Products online store.
      Buy External Serial PC Watchdog
(Clicking this link will take you to a new site for the store.)

Part# Description Price
1110 External Serial PC Watchdog with 110V AC/DC Adaptor $144.95
1110-01 External Serial PC Watchdog with Universal 110/220V AC/DC Adaptor $149.80
1110-PM-110V PC Watchdog Power Module - 110VAC Version (For use with External Serial PC Watchdog) $89.95
1110-PM-220V PC Watchdog Power Module - 220VAC Version (For use with External Serial PC Watchdog) $89.95
CBL-USB-SER-3 USB to Serial DB-9 (RS-232) Adapter - 3 foot $19.95

Note:  See images below for AC/DC adaptor types.


External Serial PC Watchdog PDF Manual
- This link is for the latest version of the External Serial Hardware Manual.

Universal DLL PDF Programmer's Manual
- This link is for the latest version of the Universal DLL Programmer's Manual which describes all the functions provided in the DLL for users who write their own application programs.

Distribution CD Image File (ZIP File)
- This link is for the current version of the distribution CD that contains all the manuals, programs, drivers, and the sample software. This includes the sample "C" and VB.net code for those users who wish to write their own aps or want to incorporate watchdog support into their existing software.

Larger Images

External Serial PC Watchdog Timer Big Image1 External Serial PC Watchdog Timer Big Image2

Since the External Serial PC Watchdog is outside the PC case, it needs a source of DC voltage to operate. For North American customers a 110V style like the one pictured on the left is supplied. For international customers you should order the PN: 1110-01 that comes with a universal type (110-220VAC) with multiple plugs like the one pictured on the right.

If you would like to source your own AC/DC adaptor then this is what you need:
    Output: 7.5 - 12V DC - 75mA minimum - 2.1mm power plug with center pin positive (+)
Let us know if you supply your own adaptor and we will issue a credit off the price.
PC Watchdog Timer 9V Adaptor OS Watchdog Timer International 9V Adaptor
110V AC/DC Supply 110-220V  AC/DC Supply
Universal type for most countries.

Here are images of the two styles of optional AC Power Modules available.
The 110V version plugs directly into an outlet and it has switched outlet on the top that is rated to switch 10A or 1200W. It is UL & CSA rated.
The 220VAC version has IEC plugs on each end. It is rated for 208-240V and can switch 12A.
PC Watchdog Timer 110V AC Power Module PC Watchdog Timer 220V AC Power Module
110VAC Power Module 220VAC Power Module
Includes IEC power cable between PC and power module