Pag. 50 of 52
- Troubleshooting / Communication protocol
12.3 Other problems and solutions
1) The actual flow inside the pipe is not standstill, but the instrument displays 0.0000 for the flow rate, and ‘
R
’
displaying signal strength and the signal quality Q (value) has a satisfactory value.
The problem are likely caused by the user who has used the ‘Set Zero’ function on this non-standstill flowing
pipe. To solve this problem, use the ‘Reset Zero’ function on menu window
M43
.
2) The displayed flow rate is much lower or much higher than the actual flow rate in the pipe under normal working
conditions.
a) There is probably an offset value wrongly entered by the user in M44. Enter ‘0’ in M44.
b) Check the transducers installation
c) There is a ‘Zero Point’ setted. Try to ‘zero’ the instrument by using M42 and make sure that the flow inside
the pipe should be standstill.
13. COMMUNICATION PROTOCOL
13.1 General
The
DIMPU
has a
RS485
standard communication interface and a complete set of
MODBUS
communication protocol.
13.2 The protocol
The Protocol isa composed by a set of basic commands (string in ASCII format) ending with a carriage return (CR)
and line feed (LF). Commonly used commands are listed below:
Command Function
Data Format
DQD(CR) Return flow rate per day
±d.ddddddE±dd(CR) LF *
DQH(CR) Return flow rate per hour
±d.ddddddE±dd(CR) LF
DQM(CR) Return flow rate per minute
±d.ddddddE±dd(CR) LF
DQS(CR)
Return flow rate per second
±d.ddddddE±dd(CR) LF
DV(CR)
Return flow velocity
±d.ddddddE±dd(CR) LF
DI+(CR)
Return POS totalizer
±dddddddE±d(CR) LF **
DI-(CR)
Return NEG totalizer
±dddddddE±d(CR) LF
DIN(CR)
Return NET totalizer
±dddddddE±d(CR) LF
DID(CR)
Return Identification Number
ddddd(CR) LF
DL(CR)
Return signal strength and quality
S=ddd,ddd Q=dd (CR)(LF)
DT(CR)
Return date and time
yy-mm-dd hh:mm:ss(CR)(LF)
M@(CR)*** Send a key value as if a key is pressed
LCD(CR)
Return the current window display
FOdddd(CR) Force the FO output with a frequency in dddd Hz
ESN(CR)
Return the ESN for the instrument
Dddddddd(CR)(LF)
RING(CR) Handshaking Request by a MODEM
OK(CR)
Response from a MODEM
No action
GA
Command for GSM messaging
Please contact factory for detail
GB
Command for GSM messaging
GC
Command for GSM messaging
DUMP(CR) Return the buffer content
In ASCII string format
DUMP0(CR) Clear the whole buffer
In ASCII string format
DUMP1(CR) Return the whole buffer content
In ASCII string Format, 24KB in length
W
Prefix before an Identification Number in a network environment. The IDN is a word, ranging
0-65534.
N
Prefix before an Identification Number in a network environment. The IDN is a single byte value,
ranging 00-255.
P
Prefix before any command
&
Command connector to make a longer command by combining up to 6 commands
Notes
*
CR = Carriage Return e LF= Line Feed.
**
‘d’ = digit numerico 0-9
*** @ stands for the key value, e.g., 30H for the ‘0’ key.
