Hach Ultra ORBISPHERE 510, Operator'S Manual

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Orbisphere 510/511/512 Analyzers - Glossary 133 of 138
Operator Manual
ORBISPHERE
RS-232
RS-232 is a serial communication standard providing asynchronous
communication capabilities with hardware flow control, software flow
control, and parity check. Maximum transmission distance is up to 15
meters at a max. 20,000 bps. A converter is required to interface
RS-232 with RS-422 or RS-485.
RS-422
RS-422 is intended for point-to-point communications. It provides
much longer transmission distance but less signal line compares to
RS-232. RS-422 adopts differential transmission technology and thus
provides high-speed transmission up to 10mbps and maximum
transmission distance up to 1.2km/110kbps.
RS-485
RS-485 is an enhanced version of RS-422 and is used for multipoint
communications, meaning that many devices may be connected to a
single signal cable. It is compatible to RS-422 interface and provides
2 wire bus topology.
Serial communication
Serial communication represents a connection in a computer system
in which the bits of a byte are transmitted sequentially over a single
wire.
Single twisted pair
In this version, all devices are connected to a single Twisted Pair.
Thus, all of them must have drivers with tri-state outputs (including
the Master). Communication goes over the single line in both
directions. It is important to prevent more devices from transmitting at
once (software problem).
TPO and TPA
Total package oxygen (TPO) is a calculated value that combines
dissolved and headspace oxygen (i.e. the mass of oxygen in the
liquid plus the oxygen in the headspace, divided by the volume of
liquid in the package). It is the amount of oxygen in a package that
can react with the beverage in that package.
Total package air (TPA) is the same combination but given in air
content. This comes from early wet lab techniques that absorbed the
CO
2
of the package. The volume of gas remaining was called “air”,
but which is not strictly correct as the oxygen to nitrogen ratio is not
identical to real air due to the oxygen consumption by sensitive
compounds in the beverage.
USB
Universal Serial Bus. An external peripheral interface standard for
communication between a computer and external peripherals over a
cable using bi-serial transmission.
The USB host uses a type A connector, and the USB peripheral uses
a type B connector.
Table A-2: Generic Terms and Definitions