CM4 Four-Point Continuous Monitor
CM4 Technical Manual
E-34
E.8 Glossary
The following terms are used in this manual:
Byte: A byte is a collection of 8 bits (or pieces) of information used
in the communication process. A byte refers to these 8 bits as a single
entity. Each bit has a value of either 0 or 1.
Communication: The act or process of passing digital information
between two points.
Data: Information that is transferred between the equipment and the
CM4 monitor. Data refers to the information contained within a packet
(see Packet). This information may be gas concentration, date, or
other information.
Equipment: This term is used to refer to the master device which is
used to communicate with the CM4 monitor(s). The equipment can
be a personal computer (PC) or other device capable of performing
the digital communications described in this protocol.
Handshake: The process of acknowledging a communication has
been received. The CM4 monitor uses ACK/NAK responses.
Hexadecimal: A type of numbering system with a base of 16. In this
numerical system, numbers 10 through 15 are represented by the
letters A through F respectively. The shortened version of the word
hexadecimal is generally “Hex,” as in “Hex 42.” “0x” is the notation used
in this manual for hexadecimal (e.g. 0x42).
Instrument: This term is used to refer to the CM4 four-point continuous
monitor.
Master: Another computer which communicates with slaves using
the CM4 protocol.
Packet: A block of information that is passed between the instrument and
the equipment. A packet is made from many bytes of information.
Protocol: The manner in which data is transferred and the format used
for the transfer. CM4 protocol refers to the packets of transferred data
the CM4 instrument recognizes.
Slave: The MDA Scientific CM4 gas monitor. A network may have
several slaves.
Time-Out: The maximum amount of time allowed between the time
the last byte of a packet is sent from the “master” device to the time
the “slave” device responds. The time-out period for this protocol is
one second.
珠海司福斯特科技有限公司
www.safedtech.com
