User manual
28 - UR4848 - User manual UR4848 - User manual - 29
Parameter
co.t.c.
has the same meaning as the heating time cycle
t.c.
Parameter
coo.f.
(cooling uid) pre-selects the proportional band multiplier
P.b.M.
and the cooling P.I.D. time cycle
co.t.c.
basing on the type of cooling uid:
coo.F.
Cooling uid type
P.b.M. co.t.c
Air
Air 1.00 10
oiL
Oil 1.25 4
H2o
Water 2.50 2
Once selected, parameter
coo.f.
, parameters
P.b.M.
,
oud.b.
and
co.t.c.
can ho-
wever be changed.
8 Serial Communication
UR484803, equipped with RS485, can receive and broadcast data via serial
communication using MODBUS RTU protocol. The device can only be con-
gured as a Slave. This function enables the control of multiple controllers con-
nected to a supervisory system (SCADA).
Each controller responds to a master query only if the query contains the same
address as that in the parameter
SL.Ad.
The permitted addresses range from 1 to 254 and there must not be controllers
with the same address on the same line.
Address 255 can be used by the master to communicate with all the connected
equipment (broadcast mode), while with 0 all the devices receive the com-
mand, but no response is expected.
UR4848 can introduce a delay (in milliseconds) in the response to the master
request. This delay must be set on parameter 72
se.de.
Each parameter change is saved by the controller on EEPROM memory (100000
writing cycles), while the setpoints are saved with a delay of ten seconds after
the last change.
NB: changes made to Words that are dierent from those reported in the fol-
lowing table can lead to malfunction.
Modbus RTU protocol features
Baud-rate
Selection on parameter 70
bd.rt.
:
4.8 k
4.800 bit/Sec.
9.6 k
9.600 bit/Sec.
19.2k
19.200 bit/Sec.
28.8k
28.800 bit/Sec.
38.4k
38.400 bit/Sec.
57.6k
57.600 bit/Sec.
Format 8, N, 1 (8 bit, no parity, 1 stop)
Supported
functions
WORD READING (max 20 word) (0x03, 0x04)
SINGLE WORD WRITING (0x06)
MULTIPLE WORDS WRITING (max 20 word) (0x10)
Looking at the table here below it is possible to nd all available addresses and
functions:
RO Read Only R/W Read / Write WO Write Only
Modbus
Address
Description
Read
Only
Reset
value
0 Device type RO EEPROM
1 Software version RO EEPROM
5 Slave address R/W EEPROM
6 Boot version RO EEPROM
50 Automatic addressing WO -
51 System code comparison WO -
500 Loading default values (write 9999) R/W 0
510 Setpoints storing time in eeprom (0-60 s) R/W 10
999 Process subjected to the visualization lter RO -
1000
Process (degrees.tenths for temperature sensors;
digits for linear sensors)
RO -
1001 Setpoint 1 R/W EEPROM
1002 Setpoint 2 R/W EEPROM
1003 Setpoint 3 R/W EEPROM
1004 Setpoint 4 R/W EEPROM
1005 Alarm 1 R/W EEPROM
1006 Alarm 2 R/W EEPROM
1007 Alarm 3 R/W EEPROM
1008 Setpoint gradient RO EEPROM