Frequently Asked Questions
Automated Data Logging
A natural extension of remote control and monitoring of a site is the desire to add automatic logging through a data connection. The RFC-1/B has a few accessories that can help address this issue.
- Model MA-2 Modem Adapter
- Model PA-2 Parallel Printer Adapter
- Model RS-232 Serial Data Adapter
Each of these accessories provides a data interface to the RFC-1/B. The standard voice mode is still available when one of the data accessories is used.
This device adds a 2400 baud data modem to the RFC-1/B. In the Internet connected world a 2400 baud connection sounds slow and it is. However, it provides enough bandwidth to transfer data to and from the RFC-1/B. Given the electrical interference at most transmitter sites, a 2400 baud connection is often as good as it gets.
Parallel Printer Adapter
This device adds a parallel printer port to the RFC-1/B. This is used to log data directly to a printer that located at the transmitter site. Parallel printers are legacy devices now. They are cheap and relatively easy to find used or even discarded.
There is no immediate plan to replace the PA-2 with a USB solution. Making USB devices like mice or keyboards is easy. But implementing a USB host to drive a USB device is much more involved. USB printers require device specific drivers. They lack the ability to print simple text from unsophisticated devices like the RFC-1/B.
Serial Data Adapter
This device adds an RS-232 serial data port to the RFC-1/B. The serial port provides bi-directional communication so it can be used for both logging and control. The RFC-1/B can transmit telemetry readings over the serial port. That data can be captured by a variety of devices and stored or re-transmitted over another medium.
Intelligent Rack Adapter
The RAK-1 Intelligent Rack Adapter adds both a modem adapter and a parallel printer adapter. Both local and remote data logging techniques will work with this device.
Software to log data from the RFC-1/B is available from third party sources. See the Links section to the right for sites that offer software for use with the RFC-1/B.
Sine Systems develops embedded hardware devices. We welcome software developers to code logging and control software for the RFC-1/B as this is not our area of expertise.
There are two methods for automatic data collection. The RFC-1/B can be programmed to send data to a capturing device at pre-determined intervals. Or, a PC can send commands to poll the RFC-1/B for the data. Polling is more flexible because the PC can perform complex tasks but the setup requires considerably more effort.
Timed Data Delivery
This method of automatic data logging is relatively easy to setup. The RFC-1/B is programmed to send a set of readings to a local or remote computer at a pre-determined interval. The receiving computer can be any system running terminal emulation software that can receive and store an ASCII data stream.
The programming in the RFC-1/B requires one action sequence that holds a print instruction. The print instruction will be either 8-8 or 8-9 depending on whether the logging computer is local or remote. If the remote remote print instruction is used, the RFC-1/B assumes a modem is connected and automatically dials telephone number F.
One or more date/time triggers must be set to activate the action sequence for data to be sent. Programming the RFC-1/B to send data every hour is easy by taking advantage of default match conditions. Program a single date/time trigger to match every month, every day and every hour.
Polled Data Acquisition or Control
In this method of data logging a computer requests the data from the RFC-1/B by sending commands as if I user is interacting with the remote control. Any command that can be issued from a remote phone can be issued over the serial data link so this method allows for both logging and control.
This allows for a great deal of flexibility and customization but the controlling program must mimic the behavior of a human user for this to work correctly. This means that the controlling program must "listen" to the prompts from the RFC-1/B and respond accordingly.
The RFC-1/B is consistent in the way it responds to commands. Responses are the same in voice and data mode. Use the auto-scan command "64" as a shortcut to retrieving a complete set of channel readings with one command. The auto-scan starts at channel 00 and the ending channel is programmable.