EZT-570S User Communication Reference Manual
A.3
Decode –
This is the reverse of encode. When a piece of data has information embedded in it,
decode is to extract that information. Example: to extract an “A” from 01000001.
Duplex –
The ability to send and receive data at the same time. “To listen and talk at the same time.”
EIA-232 –
Electronic Industries Association developed this standard hardware interface to allow one
device to talk to another device in full duplex mode. This method uses a differential voltage between
one wire and ground. Also called an unbalanced system since the ground wire carries the sum of
current of all lines. Transmission is limited to about 50 feet.
EIA-485 –
Electronic Industries Association developed this standard hardware interface to allow up to
32 devices to be on a bus at one time. This method uses a differential voltage between two wires.
Also called a balanced system since each wire carries the same current value. This has the
advantage of being immune to outside electrical disturbances.
EIA/TIA -232 and -485 –
Data communications standards set by the Electronic Industries Association
and Telecommunications Industry Association. Formerly referred to as RS- (Recommended
Standard). (See EIA-232 and EIA-485)
Electronic Industries Association (EIA) –
An association in the US that establishes standards for
electronics and data communications.
Encode –
To embed information into a piece of data. This is the reverse of decode. Example: let
01000001 stand for an “A”.
Error Correction –
When an inconsistency is in the data, a method is used to detect and/or return
the data to its correct value. This can be done through several methods, parity, checksum and CRC
(cyclic redundancy checksum) area three of these.
Even –
This term is used with parity. See parity.
Firmware –
Instruction or data stored in an IC (integrated circuit) or on a read only disk. This data is
programmed once and cannot easily be changed as software can.
Full Duplex –
Full is used to mean the duplex’s full capability. The ability to send and receive data at
the same time. The same as duplex.
GPIB –
See IEEE488
Half Duplex –
The ability to send or receive data, but not at the same time. “To listen or talk, but not
both at the same time.”
Handshake (Handshaking) –
Exchange of predetermined signals between two devices establishing
a connection. Using extra wires or software signals to coordinate communications, signals can be
sent to tell the transmitter the current status of the other device receiver. Example: Are you busy or
are you ready?
Hex or Hexadecimal –
Number based system where sixteen characters exist, 0 to 9, A to F.
Counting is 0..9,A,B,C...
HMI –
Human to Machine Interface typically performed in software on a personal computer. Also
called MMI.
Terms and Definitions (cont’d)
