This indicates a fault in the structure of the remainder of a complex request, such as that the implied length is incorrect.
#Modbus server error code#
If a request is submitted with a starting register of 96 and a quantity of registers of 5, then the request will fail with Exception code 0x02 "Illegal Data Address" since it attempts to operate on registers 96, 97, 98, 99 and 100, and there is no register with address 100.Ī value contained in the query data field is not an allowable value for the server (or slave). If a request is submitted with a starting register address of 96 and a quantity of registers of 4, then the request will operate successfully (address-wise at least) on registers 96, 97, 98, 99. For a controller with 100 registers, the PDU addresses the first register as 0, and the last one as 99.
More specifically, the combination of reference number and transfer length is invalid. The data address received in the query is not an allowable address for the server (or slave). It could also indicate that the server (or slave) is in the wrong state to process a request of this type for example, because it is unconfigured and is being asked to return registered values. This may be because the function code is only applicable to newer devices and was not implemented in the unit selected. Here is a list of things I've tried: -deleting/creating new Modbus IO server -verifying that opening a VISA terminal in NI Max that the ports are able to communicate -reformated the cRIO-9035 -created a new project (attached) with simple library I'm at a loss here as to what else I can try. The function code received in the query is not an allowable action for the server (or slave). But subsequent launches, I get the error codes above.
#Modbus server error manual#
Please refer to the specific PLC user manual for further details.
#Modbus server error password#
The Multi-level Password can be invoked by creating a Password with an upper case " A" followed by seven numbers ( e.g., A1234567). This allows Password protection while not locking the communication port to an operator interface. DirectLogic PLCs support Multi-level Password Protection of the ladder program. The Mode Switch of the PLC must be in the ( TERM) position in order for the C-more Panel to communicate with the PLC. Note: When using Automation Direct DirectLogic PLCs: 1. Note: The following Errors are generated from the designated PLC, monitored by the C-more Panel, and displayed on the panel's screen if active. Please refer to the PLC manufacturer's documentation for additional and up-to-date information. To see a link to the C-more Errors Table, which provides Error Codes specific to the C-more Panel, click the green text. These values, specific to the Modbus protocols, appear in the table below. The error message is displayed across the top of the panel screen.Įrror Code P499 shows any Errors that are generated by the connected PLC. The P499 Error Message includes a four-digit hexadecimal value displayed at the end of the message. AutomationDirect Modbus (Koyo Addressing).When you read from your slave the server call the function _read_holding_registers that return the result of _read_registers, but when it reach the call to _get_block_and_offset it raise ModbusError(defines.ILLEGAL_DATA_ADDRESS) because the conditions address >= block.starting_address and block.size >= offset + length are not satisfied, so the return block, offset is never reached.The following table provides reference information for Error Codes specific to the Modbus protocols: Result_test = modbus_client.execute(1, mbdefines.READ_HOLDING_REGISTERS, 40003, 3)Īs you can see on github there is a function called _get_block_and_offset that is called by _read_registers. Slave_1.add_block(point, cst.HOLDING_REGISTERS, addr, 3) You can also create a single block and read it: def add_test(): Result_test_2 = modbus_client.execute(1, mbdefines.READ_HOLDING_REGISTERS, 40004, 2) Self.slave_1.set_values(point, addr, (16560, 0))īoth block can be read, but with two different commands: result_test_1 = modbus_client.execute(1, mbdefines.READ_HOLDING_REGISTERS, 40003, 1) AutomationDirect Modbus Error Codes 0x0002. Self.slave_1.add_block(point, mbdefines.HOLDING_REGISTERS, addr, 2) Self.slave_1.add_block(point, mbdefines.HOLDING_REGISTERS, addr, 1) The problem is that you create two different blocks.
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