Honeywell S4965V3250 Functional Description page 30

Title: Functional description S4965V3250
Modbus communication
The ESYS controller is a slave in the communication. The ESYS is tested for interconnection with MVC Building controller
from Honeywell via C Bus interface. Maximum of 32 devices can be connected on the bus. It means one master (MVC) and
up to 31 ESYS controllers.
Modbus address selection
Modbus slave address can be selected by set of resistors or by a parameter in EEPROM.

If the parameter in EEPROM is set to 0 then address is determined by the resistors value as written below.

If not, the address from EEEPROM is used.
Adress selected via resistors
The address range from 1 to 247 is supported and can be assigned to the controller. The controller address is defined by a
combination of external resistors connected to low voltage inputs on connector X3.

Modbus Address input (X3 PIN6):
The input defines the "base" address ( 0 - 15 )
o

Modbus Address Range input (X3 PIN7):
The input defines the "offset" of the base address ( 0 - 15 )
o
The formula to get the final slave address is:
Modbus slave address = Modbus base address + Modbus address offset x 16
If calculated address is 0, the address 1 is set. If calculated address is higher than 247, the address 247 is set.
The resistor table for proper address selection is here:
For proper address selection the resistors from the E24 series with 5% or better tolerance are suitable.
Adress selected via EEPROM
The absolute slave address is saved in EEPROM (see Modbus Slave Address) and could be changed by High byte of
message ID 1537. The effect for next communication with ESYS controller is available immediately after value written.
First issue.
SW update and add parameter into list ModBus communication.
Address base / offset
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0
Description
Heating & Cooling Appliance Controls
Doc.: S4965V3250E20
Resistor value [Ω]
< 620
1 300
2 200
3 300
4 300
5 600
7 500
9 100
12 000
15 000
20 000
27 000
36 000
51 000
91 000
240 000
> 560 000
Sign. E.C.N.
I.Mariscak 0131527
I.Mariscak
Honeywell
Date Rev.
27-Jun-2016 A
03-Aug-2016 B
Page 30/33