NOVUS AUTOMATION
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6.
MODBUS PROTOCOL
DigiRail Connect
is compatible with the Modbus protocol, a data communication protocol used to connect the device to system control and data
acquisition (SCADA).
6.1
COMMANDS
6.1.1
READ HOLDING REGISTERS – 0x03
This command can be used to read the value of one or even the maximum number of consecutive registers.
6.1.2
WRITE HOLDING REGISTERS – 0x06
This command can be used to write in a register.
6.1.3
WRITE MULTIPLE HOLDING REGISTERS – 0x16
This command can be used to write in multiple registers.
6.2
REGISTERS TABLE
Following is the table of registers supported by the device:
MODBUS
ADDRESS
REGISTER
DESCRIPTION
0
HR_NUM_SERIE_LO
Device serial number (2 registers).
1
HR_NUM_SERIE_HI
2
HR_HW_SET_LO
Hardware configuration.
There are two 16-bit registers. Each of the bits represents the pres-
ence of a device or channel:
2 HR_HW_SET_LO
3 HR_HW_SET_HI
The lower part (HR_HW_SET_LO) is composed of bits from 0 to 15.
The upper part (HR_HW_SET_HI) is composed of bits from 16 to 31.
BIT 0:
DI0: Digital Input 1;
BIT 1:
DI1: Digital Input 2;
BIT 2:
DI2: Digital Input 3;
BIT 3:
DI3: Digital Input 4;
BIT 4:
DI4: Digital Input 5;
BIT 5:
DI5: Digital Input 6;
BIT 6:
DI6: Digital Input 7;
BIT 7:
DI7: Digital Input 8.
BIT 8:
DO0: Digital Output 1;
BIT 9:
DO1: Digital Output 2;
BIT10:
DO2: Digital Output 3;
BIT11:
DO3: Digital Output 4;
BIT12:
DO4: Digital Output 5;
BIT13:
DO5: Digital Output 6;
BIT14:
DO6: Digital Output 7;
BIT15:
DO7: Digital Output 8.
BIT16:
DO0_Relay: Relay Output 1;
BIT17:
DO1_Relay: Relay Output 2;
BIT18:
DO2_Relay: Relay Output 3;
BIT19:
DO3_Relay: Relay Output 4;
BIT20:
DO4_Relay: Relay Output 5;
BIT21:
DO5_Relay: Relay Output 6;
BIT22:
DO6_Relay: Relay Output 7;
BIT23:
DO7_Relay: Relay Output 8.
3
HR_HW_SET_HI