Remote data logging from boiler controller
NC Automation Engineering CC, an automation project house established in 1988 and dedicated to
quality engineering solutions, were
approached by a customer who wanted to monitor the long term performance of a number of electrical steam boilers situated over a wide geographical
area. The current solution was to use a number of laptop computers, running custom software, left on site to interrogate the boiler controller
and log certain measurements at regular intervals. Each laptop computer would have to be dropped off and fetched a few weeks later from remote
sites to retrieve the data, obviously making the laptops vulnerable to theft. The cost of the laptops, travelling between sites and time taken to
retrieve and report on the data made the whole exercise costly and inefficient.
NC Automation designed a small, wall mountable, lockable, IP65 compliant box for the customer containing a TelePAD connected to a cell modem. Power
is provided by a battery which is recharged with a trickle charger. The TelePAD is connected to the boiler controller serial port and runs a script
which, at a user defined interval interrogates the controller via its serial port, then timestamps and logs the data returned (steam measurements)
to a CSV (comma separated variable) file in the TelePAD flash memory. The TelePAD provided enough memory to store around 3 months data at typical
logging rates. This logged data can then be retrieved via any PC, either locally with a null modem cable, or remotely using a modem and establishing
an authenticated dial-up connection to the TelePAD. The logged data file can then be transferred using Internet Explorer or a ftp session. The CSV
report file can be opened directly in Microsoft Excel.
The TelePAD was found to be ideal for this remote data logging application providing data storage, serial communications, data security, open standard
platforms for data retrieval and configuration changes in a robust (no blue screens!), small package. All this at a reasonable cost! The SAN Script
option provided the ideal development environment to implement the boiler controller serial protocol and write the report files.
For the customer, the unit can be set up on site and left safely until needed elsewhere. The historical report file is automatically generated and
can be retrieved into Excel from anywhere, at any time, for the price of a phone call thus making the reporting mechanism more convenient, faster,
simpler and economically viable.
http://www.ncauto.co.za
