Gentec-EO QUAD-4Track - Manual (Page 10)

QUAD-4Track User’s Manual Revision 2.1 10
Communications with Host PC
The QUAD-4TRACK Instrument communicates with the host PC via a USB port. The
device supports full speed USB 2.0. The host P.C must have the QUAD-4TRACK
Instrument USB drivers installed. These drivers are installed by the disc supplied with the
QUAD-4TRACK Instrument. The Application Software is written in LabView and uses
the NI-VISA software from National Instruments to affect a communication link with the
QUAD-4TRACK Instrument. The implementation of the port in the host PC is
accomplished via a Virtual Com Port, or VCP. This in effect mimics a standard com port
so that the user can take advantage of the ease of developing custom applications with
existing terminal emulators.
The Ports Settings are:
Baud Rate : 115200
Data Bits : 8
Stop Bits : 1
Parity : None
Flow Control : None
The host PC must have the QUAD-4TRACK USB drivers installed. These drivers are
installed by the disc supplied with the QUAD-4TRACK instrument. The QUAD-
4TRACK instrument will use the highest available PC baud rate. PC’s running a
language that uses an alphabet such as English generally will have a maximum baud rate
of 921600. PC’s using a symbol based language such as Japanese run slower baud rates,
usually with a maximum of 115200. This restriction drives the maximum rate used in the
QUAD-4TRACK.
Data Format
Measurement Data is sent from the QUAD-4TRACK Instrument as a Hexadecimal
string. The supplied LabView VIs parse this data into numeric values.
Pulse amplitude for each channel, Measurement Range, and time stamp information are
sent.
The format is: AAAAAAAAAAAARPPPPPPPPCRLF
Where AAA is the pulse amplitude in ADC counts, for each of the 4 channels. R is the
range index of the range used to measure the data. PPPPPPPP is the pulse time stamp.
The values are followed by a carriage return and a line feed.
The final byte of the pulse amplitude consists of 4 bits of data in the high nibble,
followed by 0x04, the end of transmission character, in the low nibble. This is dome
because the data is sent over the com port, and is also sent to the secondary processor.