The data analysis offered on line by the COULTER EPICS MDADS software has been found in many laboratories to be inadequate and for some processes erroneous. Alteration or enhancement of the software by an individual user, which could tailor the system to local requirements is not permitted by the manufacturer. Hence the transfer of EPICS data to a separate computer system for routine processing is essential to the efficient running of a flow cytometry service.
MDADS software support for this function is provided by the 'TRANSMIT' feature of the 'DISK FUNCTIONS' menu. As in all MDADS routines this requires the separate keying in of each file for transfer.
A better method is in use in our laboratory using standard HUMAN INTERFACE (HI) commands that are present in the MDADS system but not documented by COULTER. This method uses a set of HI command files, the serial and parallel lines and the receiving system, in our case a FORTRAN program running as a foreground or background process in RT-11 or as a task under RSX on a PDP11 computer.
The EPICS operator simply enters the HI and invokes one of three command files:
TRANSFER (pathname) TO :PDP: !immediate transfer
SPOOL (pathname) !marks files for batch transfer
DESPOOL TO :PDP: !transfers spooled files
'Pathname' in each case may be constructed using the standard iRMX86 wild cards (* and ?). It is this feature that makes this method so flexible.
The TRANSFER and SPOOL commands' actual parameter lists may also contain processing flags for use by the PDP batch processing programs.
The receiving program writes all incoming data to disk then, on interpreting the process attributes, performs the required data analysis. The batch mode is envisaged for use in after hours processing and transfer of data to our VAX data storage system.