DISP33 - Virtual Chart Recorder Display

Printer Friendly

DISP33 is a program that graphically displays data from RMS Instruments' GR33A family of Chart Recorders in real time. The program uses an IBM®-compatible computer to create a display that resembles the output of a chart recorder vertical traces on a chart. Traces are drawn in different colours, with matching labels. Several charts, each with its own gain and zero point, can be displayed on one screen. Up to four screens can be defined in a single configuration. (The GR33A family consists of GR33A, GR34A, GR33AP, GR33U2, and GR33U2S chart recorders.)

DISP33 complements the functions of traditional recording on chart paper, offering (a) an alternative means to monitor in real-time, perhaps remotely, the same signals being recorded on paper, and (b) the primary monitoring device in applications where paper recording is only "on demand".


  • Displays up to 16 traces at a time
  • Displays time stamp and time axis on each chart
  • Allows zooming on any given trace
  • The user may control size, position, label, span and zero position of charts
  • Trace scrolling may be adjusted independently for each chart
  • Recorder channels may be assigned to traces in any order
  • Optionally logs trace data to a disk file while receiving and displaying
  • Allows remote monitoring via modem
  • Works even when the chart is off (paper recording only "on demand")
  • Allows for keyboard or mouse control while running
  • Allows for a screen snapshot to be sent to a file or printer

Figure 1

As an example, in an electrical utilities power monitoring application we may find a computer running DISP33 at a central station, with chart recorders (GR33U2) at various remote sites monitoring AC voltage and/or frequency fluctuations. The recorders are contacted periodically via modem, giving the operator access to the information in exactly the same format shown on the chart (Figure 1).

In another application, when the chart recorder is integrated into a data acquisition system (e.g., RMS Instruments' DGR33A or DAS8), all the information sent to the recorder is also available for real-time viewing on the computer's screen. The only additional hardware required is a cable (RS-232) between the output serial port in the recorder, and one of the COM ports in the PC. The configuration of DISP33 is fully programmable.

Figure 2

For example, in a geophysical data acquisition environment, the user may define a configuration with one screen consisting of four charts: (a) MAG traces, (b) fourth difference of MAG, (c) VLF, and (d) radio altimeter (Figure 2). The remaining three screens could be configured with additional information, or with a different arrangement of the same traces. The operator may readily switch from one screen to another with a couple of keystrokes, or using the mouse.

Minimum Requirements:

IBM®-compatible computer with 386, VGA,1 Mbyte of RAM, and a serial port.
MS-DOS 5.0.