Memory areas
Predefined memory areas are available for addressing the process data. Optionally, you can access the input and output data areas bit by bit (using coils) or word by word.
Register area for word by word access
| Modbus Address area | Use | Access | Access type | Meaning | |
| 1 – 256 | Input Register | Read Only | Holding/Input * | Values that the other RevPi Gate supplies. | |
| 1025 – 1280 | Output Register | Read/Write | Holding | Values that are supplied to the other RevPi Gate. | |
| 4097/0x1001 | Gateway Status | Read Only | Holding | Displays the connection status to the other RevPi Gate. | |
| 0x01 | Initialisation, checking Hardware. | ||||
| 0x02 | Connection to the other gateway component is checked. | ||||
| 0x03 | Other gateway component detected. | ||||
| 0x04 | Communication to the other gateway component established. | ||||
| 4098/0x1002 | Fieldbus status of the other gateway component | Read Only | Holding | 0x00 | Fieldbus not connected. Check all Connections. |
| 0x01 | Fieldbus connected, no data communication. Check whether an IP address is set. | ||||
| 0x02 | Gateway component configured, no data communication. | ||||
| 0x03 | Cyclical data Exchange. | ||||
| 4099/0x1003 | IP Address | Read/Write | Holding | IP Address High Word | |
| 4100/0x1004 | IP Address | Read/Write | Holding | IP Address Low Word | |
| 4101/0x1005 | Network Mask | Read/Write | Holding | Network Mask High Word | |
| 4102/0x1006 | Network Mask | Read/Write | Holding | Network Mask Low Word | |
| 4103/0x1007 | Gateway Address | Read/Write | Holding | Gateway Address High Word | |
| 4104/0x1008 | Gateway Address | Read/Write | Holding | Gateway Address Low Word | |
| 4105/0x1009 | Max. Number of Modbus/TCP connections | Read/Write | Holding | Shows the maximum number of Modbus/TCP connections that can exist simultaneously.
Value Range: 2-20 |
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| 4106/0x100a | Current number of Modbus/TCP connections | Read Only | Holding | Shows the current number of Modbus/TCP Connections. | |
| 4107/0x101b | Write Timeout | Read/Write | Holding | The write timeout function is active if there is a value > 0 in this Register.
It specifies the time interval at which at least one of the output registers must be written As soon as the time has elapsed since the last write, all output registers are set to the default value 0. |
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| 4108/0x100c | Reset | Read/Write | Holding | Restarts the RevPi Gate if 0x4b42 is written here.
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*Input and holding registers are not distinguished. They can be read via function code 0x04
Register area for bit by bit access
| Address area | Use | Access | Access type | Meaning |
| 1 – 3840 | Input Bits (Coil) | Read Only | Holding/Input* | Values that the other gateway component supplies. |
| 16385 – 20224 | Output Bits (Coil) | Read/Write | Holding | Values that are supplied to the other gateway component. |
*Input and Holding Register are not differentiated. They can be read using function code 0x004.
Functions
You can access the data area of the gateway component using the following functions:
| Function code | Use | Description | Max. size per telegram |
| 0x01 | Read data bit by bit | read coils | 2000 Bit |
| 0x02 | read discrete inputs | ||
| 0x05 | Write data bit by bit | write single coil | 1 Bit |
| 0x0f | write multiple coils | 1968 Bit | |
| 0x03 | Read data word by word | read holding registers | 125 words |
| 0x04 | read input registers | ||
| 0x06 | Writedata word by word | write single register | 123 words |
| 0x10 | write multiple registers | ||
| 0x16 | mask write register | ||
| 0x17 | Read and write data word by word | read/write multiple registers | Read 125 words
Write 121 words |