Owner's manual

34 DLR3110 Rack Mount Digital Pressure Calibrator Manual
• The protocol between the “standard” full duplex and the RS485 only differ by the addition of the origin
and destination address characters.
•All functions performed via the front panel keys can also be performed via the serial full duplex
communications.
6.3.1 Full Duplex Protocol
Communications from the host computer to the DLR:
<*><DD><OO><cmd><{><data entry><}><CHECK><CR>
NOTE: Destination and origin characters (<DD> and <OO>) are only sent in RS485 format
Response from the DLR:
<:><OO><DD><cmd r><{><data resp><}><CHECK><CR>
Where:
"<",">" = Brackets are not sent
* = Message from master (host computer [2AH])
: = Response from DLR3110 (3AH)
DD = DLR unit address (two digit) if in RS485
OO = Master address (fixed at 00) if in RS485
If RS485 mode is not selected the "DD" and "OO" are not transmitted.
cmd = Three character command to DLR3110
cmd r = Three character command echoed from DLR3110
{ = Start of data character (7BH)
} = End of data character (7DH)
'{' and '}' only sent if data entry or recall.
data entry = Data entered into DLR if entry command
data resp = Data response from DLR if in response
CHECK = Optional two character check if selected
CR = Message terminator (0DH)
A "LF" character following the "CR" is ignored. All characters following the "CR"
and preceding the "*" is ignored.
6.3.2 Command Code <cmd> Description
The <cmd> consists of three (3) characters “ppt” where:
pp = the command parameter (see chart I)
t = the command type
The three (3) command types (t) are as follows:
Direct cmd code = < D > character (44H). “D” commands have no data associated with them
Examples:
•General commands (Zero, Tare, etc.)
•Display Mode commands (Gross, Peak, etc.)
•Weight calibration (Zero Cal, etc.)
Data request code = < R > character (3FH). “R” commands are requests for data from the host to the
DLR
Examples:
•Weight/pressure data
• Status
• Setup data
•Calibration data