Northern Lights OWN-ADV, Installation And User Manual

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OWN-ADV 01/12
9.2 MODBUS COMMANDS
WaveNet supports two Modbus commands “0x03 Read Holding Register (4x)” and “0x06 Write Single
Register”
To make the communication work, user need to setup something in WaveNet setting to correspond-
ing with the RSA unit. In the WaveNet Advanced menu, there is a menu “SET Modbus”, user can
setup the WaveNet device address and device baud rate there.
To use the 0x03 command to read the holding register, the user will need to set the holding register
start address, quantity of bytes to read, and the scan rate. When sending the start address, use the
following formula:
start address = register address – 40 000.
1. Obtain the correct holding register address from the register map below
2. The WaveNet device only supports reading up to 20 registers at a time; reading more than 20
registers at a time will give an illegal address error. Also be careful to not read invalid registers as the
WaveNet register map is not continuous.
3. The recommended scan rate is 1000ms. The WaveNet updates holding register address from
40050 to 40244 every 1 second.
4. All registers that are written too, and all modbus registers in the range of 1 to 10, are updated
every 250ms.
As an example, a user wanting to read the engine speed and other related parameters (the engine
speed holding address is 0x40150), would use the 0x03 command with start address 0x40150 and
quantity 20, and a scan rate of 1000ms. The user’s device will continue polling address 0x40150 to
0x40169 at 1000ms duration.
Note: There are only two addresses that support the 0x06 command, the address are 0x40098 and
0x40130.
NOTE: All parameters are assumed to be unsigned integer values unless otherwise specifi ed in the “Range” column.
Table 20 - Modbus Register Map
Register Parameter Range Read/Write Data format Units
1st Generation ModBus Support
(For new applications utilize 2nd generation support)
Warning and fault shutdown are updated by controller once every 250ms.
40001
Highest Severity
Event (Read only) bit 16 = Alarm State, bit 15-14 = Severity, Bits 13-10 = Reserved,
Bits 9-1 = Event #
40002 Previous Highest
Severity Event (R) bit 16 = Alarm State, bit 15-14 = Severity, Bits 13-1 = Event #
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9.3 REGISTER MAP