GPI Configuration
Hi,
I am Using Bailey INFI90 MFP Controllers & GPI V4 Software for Modbus RTU Communication.
In the slave system the data is available at 40010 & 40015 modbus address. So please tell me what is the equivalent modbus mapping address and where should i update it in GPI file.
Thanks in advance.
I am Using Bailey INFI90 MFP Controllers & GPI V4 Software for Modbus RTU Communication.
In the slave system the data is available at 40010 & 40015 modbus address. So please tell me what is the equivalent modbus mapping address and where should i update it in GPI file.
Thanks in advance.
Asked 2 years ago
Answers
1
Hi,
Table 5.3 in the GPI 4.0 manual (3BCA010145R1701) should answer all of your questions. The manual also explains how to modify GPI configurations.
The biggest source of confusion when adding points is probably the calculation of the point address, so here is another take on GPI PLC data table and point address fields.
The GPI PLC data table field corresponds to the modbus data table within the slave device (Coils or discrete outputs=0, contacts or discrete inputs=1, input registers=3 and holding register=4). Happily, the first digit of the modbus address defines the data table, so in your case the modbus addresses belong to the holding register data table (or Read/Write Analog(AO) in the GPI software).
Secondly, the point address is related to the 4 or 5 digits after the 1st digit of the modbus address and this number identifies the position of the element within the data table. Some vendors use an absolute addressing scheme to document the modbus tables. I.E. The number of the element within the data table and so modbus register 40010 is the 10th register in the holding register table (4). Others, including the GPI, use relative addressing and describe element as an offset from the start of the data table rather than the position of the element with the data table. I.E. for the GPI, modbus address 40010 is in the holding register table (4) and has a offset of 0009 from the beginning of the table. Therefore the GPI point addresses end up being 1 less than the absolute modbus address. If you are adding to an existing interface you should be able to work out the addressing scheme used by the slave device from the existing points.
Pay attention to the point type field as this defines whether data is read from (AOP/DOP) or written to (AIP/DIP) the modbus slave device.
You didn't specify a data type for the registers to be read. The data type determines how the 16 bit register is interpreted and you may also need to specify a new scale index if the data is signed or you wish to perform a conversion of the register value to engineering units.
Cheers, Alan
Table 5.3 in the GPI 4.0 manual (3BCA010145R1701) should answer all of your questions. The manual also explains how to modify GPI configurations.
The biggest source of confusion when adding points is probably the calculation of the point address, so here is another take on GPI PLC data table and point address fields.
The GPI PLC data table field corresponds to the modbus data table within the slave device (Coils or discrete outputs=0, contacts or discrete inputs=1, input registers=3 and holding register=4). Happily, the first digit of the modbus address defines the data table, so in your case the modbus addresses belong to the holding register data table (or Read/Write Analog(AO) in the GPI software).
Secondly, the point address is related to the 4 or 5 digits after the 1st digit of the modbus address and this number identifies the position of the element within the data table. Some vendors use an absolute addressing scheme to document the modbus tables. I.E. The number of the element within the data table and so modbus register 40010 is the 10th register in the holding register table (4). Others, including the GPI, use relative addressing and describe element as an offset from the start of the data table rather than the position of the element with the data table. I.E. for the GPI, modbus address 40010 is in the holding register table (4) and has a offset of 0009 from the beginning of the table. Therefore the GPI point addresses end up being 1 less than the absolute modbus address. If you are adding to an existing interface you should be able to work out the addressing scheme used by the slave device from the existing points.
Pay attention to the point type field as this defines whether data is read from (AOP/DOP) or written to (AIP/DIP) the modbus slave device.
You didn't specify a data type for the registers to be read. The data type determines how the 16 bit register is interpreted and you may also need to specify a new scale index if the data is signed or you wish to perform a conversion of the register value to engineering units.
Cheers, Alan
Answered 2 years ago
Source: 3BCA010145R1701
Add new comment