USB 4-20 mA data logger
Low cost solution for Walchem controllers with 4-20 mA option boards fitted. The USB 4-20 mA self powered data logger will automatically collect data for any device assigned to a given 4-20 mA option card. This enables water treatment engineers' to create detailed data files that can be downloaded to create graphs etc. and prove the performance of the controller whilst unattended. Troubleshooting of any control events are also simplified since all data points are time stamped. The user can easily set up the logging rate and start time. Download the stored data by plugging the module straight into a PC's USB port and run the free supplied software under Windows 98, 2000, XP and Vista (32 bit). The data can then be graphed, printed and exported to other applications. The data logger is supplied with a long-life lithium battery. Correct functioning of the unit is indicated by a flashing red and green LED. The data logger features a pair of screw terminals and is supplied complete with a set of measurement leads terminating in crocodile clips for easy fitment.




Product features
• 4-20 mA current loop measurement range
• Logging rates between 1s and 12 hrs
• Stores 32,000 readings
• Connection via two screw terminals
• USB interface for set-up/data download
• USB-programmable alarm thresholds
• Red and green status indication
• Replaceable internal lithium battery



LED flashing modes
The LEDs will flash in one of the following ways, assuming alarm hold is turned off.
Green single flash every 30 seconds. Logger primed and ready to start.
Green single flash every 10 seconds. Logging in progress, last stored value OK
Red single flash every 10 seconds. Logging in progress, the last stored reading is equal to or exceeds the low alarm level (if hold is turned on, then a stored value is equal to or exceeds the low alarm level)
Red double flash every 10 seconds. Logging in progress, the last stored reading is equal to or exceeds the high alarm level (if hold is turned on, then a stored value is equal to or exceeds the high alarm level)
Green single flash every 20 seconds. Low battery, logging in progress, the last stored value OK
Red single flash every 20 seconds. Low battery, logging in progress, the last stored value is equal to or exceeds the low level alarm
Red double flash every 20 seconds. Low battery, logging in progress, the last stored value is equal to or exceeds the high level alarm
Green double flash every 20 seconds. Logger is full, last stored value is OK
Red/Green single flash every 20 seconds alarm hold turned on. Logger is full, last stored value is equal to or exceeds the low or high alarm level
No LEDs flash. LEDs disabled during configuration to save battery power and increase logging duration or battery dead
By default hold is disabled. In this mode the red LED will no longer continue to flash after the logged temperature has returned from an alarm condition.