User manual - ATR244 - 19
8.11 Soft-Start Function
ATR244 is provided with two types of softstart selectable on parameter 264 SS. tY. (
“Softstart Type”
).
1 First selection (
GrAd .) enables gradient softstart. AAt starting the controller reaches setpoint basing
on the rising gradient set on parameter 266
SS. G r. (
“Softstart Gradient”
) in Unit/hour (ex. °C/h). If
parameter 269
SS . ti . (
“Softstart Time”
) is diff erent to 0, at starting when the time selected on par.
269 is elapsed, the controller stops to follow the gradient and reaches setpoint with the maximum
power.
2 Second selection (
PErc.) abilita enables output percentual softstart. On par. 268 SS. tH. it is possible to
set the threshold under which starts the softstart (
“Softstart Threshold”
). On par. 267 SS.PE. (
“Softstart
Percentage”
) an output percentage is selectable (from 0 to 100), which controller keeps until the
process exceeds the threshold set on par. 268 or until the time in minutes set on par. 269
SS . ti .
(
“Softstart Time”
word 2084).
If the Sof-Start function is active the automatic/manual Tuning function cannot be activated.
8.12 Retransmission function on analogue output
If not used as command, the analogue output can be used to retransmit process/ setpoint/ current
read by the C.T. input/ output percentage.
Select on parameter 298
r t M .1 (“Retransmission 1”) or on parameter 308 rtM.2 (“Retransmission 2”) the
value to be retransmitted and on parameter 299
r.1 . t Y . (“Retransmission 1 Type”) or on parameter 309
r.2. tY. (“Retransmission 2 Type”) the output type.
It is possible also to select on parameters 300
r.1.L.L. and 301 r.1 . u . L. or 310 r. 2.L.L. and 311 r.2. u .L. the input
value rescale limites.
9 Serial communication
ATR244-xxxxx-T is equipped with RS485 and can receive/broadcast data via serial communication
using MODBUS RTU protocol. The device can only be configured as a Slave. This function enables the
control of multiple controllers connected to a supervisory system / SCADA.
Each controller responds to a Master query only if the query contains the same address as parameter
318
sL. a d . (
“Slave Address”
).
The addresses permitted 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 command, but no response is expected.
The baud rate is selected on parameter 319
bd . rt. (
“Baud Rate”
).
ATR244 can introduce a delay (in milliseconds) of the response to the master request. This delay must
be set on parameter 321
se. d e. (
“Serial Delay”
).
Each parameter modification is saved by the controller in the EEPROM memory (100000 writing cycles),
while the setpoints are saved with a delay of 10 seconds after the last modification.
Changes made to words that are different from those reported in the following table can lead to
malfunction.
Modbus RTU protocol features
Baud-rate
Selectable on parameter 319
bd . rt.
1200bit/s 28800bit/s
2400bit/s 38400bit/s
4800bit/s 57600bit/s
9600bit/s 115200bit/s
19200bit/s
Format
Selectable on parameter 320
s. p. p.
8N1 8N2
8E1 8E2
8O1 8O2
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