HD404…
- 15 -
V1.2
4.2
C
ONFIGURATION OF THE MODELS WITH
RS485
OUTPUT
(HD404ST…)
RS485 Modbus address: each transmitter of the network is univocally identified by
an address between 1 and 247. Transmitters having the same address shall not
be present in the network. The transmitter Modbus address is equal to the sum of
the value set with the dip-switches 2…6 (value settable from 0 to 31) and the value set
with the serial command WA (value settable from 1 to 216, default = 1). By setting a
dip-switch to ON (upwards), the following values are added to the address:
Dip-switch 2 Dip-switch 3 Dip-switch 4 Dip-switch 5 Dip-switch 6
ON
16
8
4
2
1
OFF
0
0
0
0
0
Example: if the dip-switches 2 and 4 are set to ON, and the dip-switches 3,5 and 6
are set to OFF, the value set with the dip-switches is 16+4=20. If the value set with
the serial command WA is 1 (default value), the transmitter Modbus address is
20+1=21.
The dip-switches can be set even if the transmitter is powered, and the change is ef-
fective immediately.
Configuration via the RS485 serial port:
In order to change the settings, proceed as follows:
•
Connect the transmitter RS485 output to the PC RS232 (through a RS485/RS232
converter) or USB (through a RS485/USB converter, for example the RS48 ca-
ble) port. If a RS485/USB converter is used, install in the PC the related USB
drivers.
•
To enable the configuration mode, set the dip-switch 1 (the one closest to the
terminal block) to ON (upwards), then power the transmitter.
Note: the dip-switch 1 can be changed from OFF to ON even when the instru-
ment is powered; in this case it is however necessary, after setting the dip-
switch to ON, to press briefly (less than 0.5 seconds) the CAL ZERO button to
enable the configuration mode (the transmitter model information appears on
display, if present). Alternatively, power cycle the transmitter.
•
On the PC, run a serial communication software, set the baud rate to 57600 and
the communication parameters to 8N1.
•
Send the CAL START command (the command is required to change the config-
uration; to read the value of the parameters, the command is not required).
•
Send the commands given in table 4.2 to set or read the configuration parame-
ters of the transmitter (the commands that affect the speed or the flow have effect
only in the versions with SR option.
TAB. 4.2: serial commands (models with RS485 Modbus-RTU output)
Command
Description
AVGn
Set the response time of index n for the measurement:
n=0
⇒
0.125 s, n=1
⇒
1 s, n=2
⇒
2 s, n=4
⇒
4 s
AVG?
Reads the response time set for the measurement.
DU0
Shows pressure in Pa on display.
DUF
Shows flow in l/min on display (only in the versions with SR option).
DUV
Shows speed in m/s on display (only in the versions with SR option).
OPT3E
Shows alternately speed (or flow) and pressure on display.
Summary of Contents for Delta OHM HD404 Series
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