Klimor EVO -T - Communication of RS485 Master, Modbus RTU with the BMS System

74
AUTOMATION AND CONTROL SYSTEM FOR UNITS EVO-T; EVO-T COMPACT
OPERATION AND MAINTENANCE MANUAL
Name Name
Default
value
Description / Service menu
The set up
Analog outputs - Possibility to scale the 0÷10VDC output signal to 2÷10VDC signal (check signals conformity with the air damper actuator OMM, valve)
Communication
0,3 s Tcom – time for communication with Modbus device in SLAVE mode
3 s
Twait – time to wait for a reply in communication with Modbus device. A factory setting appropriate for max 9 devices with Modbus. In case of
more devices you need to increase the Twait time in line with the rule: (number of Modbus devices x Tcom) + 0.3s.
Lead temp.
history
- -
Last 15 saved measurements from the lead temperature sensor with selected record period) and provided „deviation” which is the max dierence
between the current preset temperature and last 15 measurements from the lead temperature sensor
- - -
Readout of controller inputs and outputs, possibility of input emulation and controller input forcing during normal system operation, an alarm is
reported during emulation or forcing, however the system is working.
Change
password
- -
Change of password for accessing advanced options. Default password: 1111
Note: if the password is lost or forgotten it is not possible to change advanced parameters
Restore
default
settings
- - Restoring initial values of all settings.
10. CONTROLLER COMMUNICATION
10.1 Communication of RS485 Master, Modbus RTU with the BMS
system
The controller is equipped with implementation of the
Modbus RTU protocol. In order to establish network
connection, connect RS-485 bus to the MASTER port
on the controller strip. The Modbus address is set using
jumpers located on the controllers bottom plate.
Default communication parameters:
• Baud rate: 9600 bps (it is possible to change for the
superstructure level or external HMI
• 8 frame bits
• 2 stop bits
• no parity
All variables are 32-bit values which are indicated in the
Modbus protocol as Input, Coil, Holding Register or In
-
put Register in dierent address spaces.
Reading and saving the Input and Coil type data:
Each variable is 32-bit value. E.g. a variable with address
in the 0x0008 table enables bits with the following bit
addresses: 8*32 … 9*32-1 for Input and Coil in Modbus
standard.
Reading and saving data of Holding Register and
Input Register type:
Variables in this form, to facilitate integration with BMS
systems, are made available in dierent address spaces.
-0x0000 … 0x1000 – traditional representation accord
-
ing to the following information
• Multistate – specied integral values of variable corre
-
spond to described conditions
• Decimal – 32-bit variable value is considered as integral
type with a mark,
• Fixed – xed-point type, where 8 least important bits is
assign for a decimal part while remaining 24 bits are as
-
signed for integer value with a symbol. In the result the
xed value accuracy is 1/256. In order to scale the repre
-
sented xed value into the target (specic) one, multiply
it by 1/256 = 0.00390625.
-0x1000 … 0x2000 – Fixed-format variables represent
-
ed as integral values without a decimal part
-0x2000 … 0x3000 – Fixed-format variables represent
-
ed as values with a one decimal place accuracy in deci-
mal format. Value 20,67 represented as 206
-0x3000 … 0x4000 – Fixed-format variables represent
-
ed as values with two decimal places accuracy in deci-
mal format. Value 20,67 represented as 2067
-0x4000 … 0x5000 – similarly as for 0x0000 … 0x1000
space, but variables are considered as 16-bit values. It
means that older 16-bits are not considered. The ad
-
dresses should be divided by two. For example, a var-
iable from the 0x0124 table is available in 16-bit format
at the 0x4092 Modbus address
-0x5000 … 0x6000 – similarly as for 0x1000 … 0x2000
space, but variables are considered as 16-bit values. It
means that older 16-bits are not considered. The ad
-
dresses should be divided by two. For example, a var-
iable from the 0x0124 table is available in 16-bit format
at the 0x4092 Modbus address
-0x6000 … 0x7000 – similarly as for 0x2000 … 0x3000
space, but variables are considered as 16-bit values. It
means that older 16-bits are not considered. The ad
-
dresses should be divided by two. For example, a var-
iable from the 0x0124 table is available in 16-bit format
at the 0x4092 Modbus address
-0x7000 … 0x8000 – similarly as for 0x2000 … 0x3000
space, but variables are considered as 16-bit values. It
means that older 16-bits are not considered. The ad
-
dresses should be divided by two. For example, a var-
iable from the 0x0124 table is available in 16-bit format
at the 0x4092 Modbus address.
The variables in the Multistate and Decimal representa
-
tion should not be used in the 0x1000 … 0x4000 and
0x5000 … 0x8000 address spaces because you lose the
least important 8 bits of each variable.