MSCB Software

Node software
Submaster software
PC software



The source files are under the
GPL and can be found in the download area. It is named mscbxxx where xxx is the version. It should be unzipped into an "mscb" directory. It contains following files:

PC software

On the PC side, a "C" library manages the communication with the SUBMASTER-300 through the PC parallel port. The library contains routines for addressing nodes, reading and writing channels and so on. Using this library, a simple test program could look like this:

#include "mscb.h"

int   fd, size, status;
float value;

  fd = mscb_init("lpt1");

  /* check if node #123 is alive */
  status = mscb_ping(fd, 123);
  if (status != MSCB_SUCCESS)
    printf("Node 123 doesn't respond.\n");
    return 0;

  /* output 1.25V at DAC1, assuming node is a model SCS-500 */
  value = 1.25;
  mscb_write(fd, 123, 8, &value, sizeof(value));

  /* read and display ADC1 */
  size = sizeof(value);
  mscb_read(fd, 123, 0, &value, &size);

  printf("ADC1 reads %1.2lfV\n", value);


  return 1;
For a MSCB program to run, it has to have direct access to the parallel port. While this is no problem under Windows 95/98/ME, it is not allowed under Windows NT/2000/XP and Linux. Under Linux, one can use the /dev/parport device which allows direct bit manipulations at the parallel port. This feature will be implemented soon in the MSCB library. Under Windows NT & Co., the directIO drive can be used to talk directly to the port. The driver is contained in following ZIP file:

Unpack it and follow the instructions to install it. Note that the directIO driver must be running before any MSCB program can be started.

Command line interface

A command line interface "wrapping" around the C library has been implemented, allowing users to interactive execute MSCB command. Following listing shows an example session with this program:
C:\mscb> msc
> scan
Found node "SCS-400", node addr. 1 (0x0001), group addr. 1 (0x0001)

> addr 1
Node 1 addressed

node0x1> info
Node name:        SCS-500
Node status:      0x00
Node address:     1 (0x1)
Group address:    1 (0x1)
Protocol version: 1.1
Watchdog resets:  0

 0: ADC0      32bit  1.15204 volt
 1: ADC1      32bit        0 volt
 2: ADC2      32bit        0 volt
 3: ADC3      32bit        0 volt
 4: ADC4      32bit        0 volt
 5: ADC5      32bit        0 volt
 6: ADC6      32bit        0 volt
 7: ADC7      32bit        0 volt
 8: DAC0      32bit        0 volt
 9: DAC1      32bit        0 volt
10: P1         8bit      255 (0xFF) byte

Configuration Parameters:
 0: ADCAvrg    8bit        8 (0x08) counts
 1: Gain0      8bit        0 (0x00) byte
 2: Gain1      8bit        0 (0x00) byte
 3: Gain2      8bit        0 (0x00) byte
 4: Gain3      8bit        0 (0x00) byte
 5: Gain4      8bit        0 (0x00) byte
 6: Gain5      8bit        0 (0x00) byte
 7: Gain6      8bit        0 (0x00) byte
 8: Gain7      8bit        0 (0x00) byte
 9: GainCal   32bit        1 factor
10: BipCal    32bit        0 volt

node0x1> write 8 1.25

node0x1> read 1
32bit 0x880432 volt

The scan command scans the whole bus and looks for active nodes, which then can be addressed individually.

The info command retrieves information directly from the node, while the write and read commands are uses to transfer data to/from individual channels on the node. The command line program can also be calles from scripts to perform more complicated operations.

LabView driver

A LabView driver based on the C library has been developed, so one can incorporate MSCB devices into LabView applicatoins.

Here is a screenshot of an included example application:

It writes a voltage of 0..10 V to the DAC channel 1 of node #1 and reads back the ADC from channel 3, which is connected directly to the DAC, so that the readback and the demand value are identical.

LabView logger

A simple data logger LabView application is contained in the distribution package. It reads and displays 8 data channels, logs data into a file, and sends optionally an email notification in case an alarm condition occurs. Here is a screenshot:

For further questions please contact the author.

Mar. 4th, 2003, S. Ritt