IGNORE THIS PAGE unless communications option has been ordered. When the RS232 (option 3013) or RS485 (option 3002) is
ordered, two protocols are made available, namely ASCIIbus & DIGIbus protocols. DIGIbus is the default protocol which is used for
the calibration and configuration of the instruments, and whenever the instrument is connected to master-slave systems. DIGIbus
protocol is therefore used in complex bus systems, and is NOT described here. Please contact factory for the DIGIbus protocol.
ASCIIbus, which is described here, is much easier to use as it can easily interface to third party systems with very little engineering
work required. It is a purely ASCII based (7 bit) protocol. The protocol is essentially designed for one way communications
(instrument to PC). Under the "Conn" (connection) programming menu, ASCIIbus is enabled by selecting "ASCI" to "ON". If "OFF" is
selected, the DIGIbus protocol will be active. Although designed for one way communications only, the ASCIIbus protocol contains an
address. The address range is "00" to "99".
Using address "00" : If this address is selected, the instrument will only transmit data on demand by either momentarily pressing the
'menu' key, or by transmitting a byte (any ASCII character) to the DPM. This mode is useful for interfacing to printers. In addition, field
' A A ' will contain the ASCII character "blank/space". Field ' P ' will also contain the ASCII character "blank/space".
Using address "01" to "99". If any of these addresses are used, the meter continuously transmits information at approximately 5 times
a second.
The data format string output from the indicator is (7 bit ASCII code is used):
Line Settings : 7 Data Bits, 1 Parity bit, Odd Parity, 1 Stop Bit.
Baud Rate : Selectable 2400, 4800, 9600, 19200.
Data Bits : Numerical ASCII characters : 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
Other ASCII characters : #, blank/space, +, -, CR, LF
Protocol format is : # A A S D D D D D D D D P CR LF
where : # = indicates start of message
: A A = Instrument address. ASCII 00 to 99. 00 is default.
: S = sign (polarity) ( ASCII "+" or "-" ).
: D = data bits (data for 8 numerals). See Note (1).
: P = decimal point position. ASCII 0 to 8.
: CR = ASCII carriage return.
: LF = ASCII line feed.
The output will follow the display reading. This
means that if the peak-hold option has been
ordered and activated, the communications output
will peak-hold as well.
Note 1 : This protocol allows for future expansion.
Therefore if Model 4001 is used for example, the
first four digit data will contain the ASCII character
"blank/space" and the last four digits will contain
the display reading. Similarly, if the Model 5001 is
used for example, the first 2 digit data will contain
the ASCII character "blank/space" and the last six
digits will contain the display reading.
Asciibus Protocol (for Option 3002 / 3013)Communications
Page 12
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