Abstract: A multiple port valve integrated with the function of the sample shut off valve is disclosed. The integration of the sample shut off function eliminates extra plumbing and labor costs associated with a separate sample shut off valve. Additionally, the multiple port valve integrated with the function of the sample shut off valve provides a shorter equilibration time and less tubing volume.

Abstract: A multiple port valve integrated with the function of the sample shut off valve is disclosed. The integration of the sample shut off function eliminates extra plumbing and labor costs associated with a separate sample shut off valve. Additionally, the multiple port valve integrated with the function of the sample shut off valve provides a shorter equilibration time and less tubing volume.

Abstract: Each of a plurality of programmable master devices having access to a data communication link is assigned a unique address based on the priority of that master device. The unique address of each master device is loaded into an associated counter when a link contention signal is impressed on the link by one of the master devices, and all counters begin counting down at the same time and at the same rate when the contention signal is terminated, whereby the counter with the lowest number address times out first and its associated master device can gain access to the data link. The unique address of each master device thus provides a way for higher priority master devices to lock out lower priority master devices so as to prevent simultaneous transmission on the data link and also to prevent loss of high priority data.

Abstract: The accuracy of the conversion of an analog signal to digital form is improved by amplifying the input signal by different factors and automatically utilizing the highest amplified input signal which has a voltage level within operational limitations in the analog to digital conversion process. Output data from a digital computer, based on the input data, is converted from digital form to analog form and is routed to a required location by the use of control logic and optically isolated digital signals used to address other computers.