How to Configure RevPi Gate for Modbus TCP Slave

Memory Areas

Predefined memory areas are available for addressing the process data. You can access the input and output data areas either bit by bit (using coils) or wordwise.

Register areas for wordwise access:

Modbus Address Area

Application

Access

Access Type

Meaning

1 – 256

Input register

Read only

Holding/Input *

Values provided by the other RevPi Gate

1025 – 1280

Output register

Read/Write

Holding

Values supplied to the other RevPi Gate

4097/0x1001

Gateway status

Read only

Holding

Displays the connection status to the other RevPi Gate

0x01

Initialization, checking hardware

0x02

Connection to the other RevPi Gate is checked

0x03

Another gateway component detected

0x04

Communication established to the other RevPi Gate

4098/0x1002

Fieldbus status of the other RevPi Gate

Read only

Holding

0x00

Fieldbus not connected. Check all connections.

0x01

Fieldbus connected, no data communication. Check whether an IP address is set.

0x02

RevPi Gate 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

Displays the maximum number of Modbus/TCP connections that can exist simultaneously.

Value range 2-20

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 this register contains a value > 0. 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.

4108/0x100c

Reset

Read/write

Holding

Restarts the RevPi Gate if 0x4b42 is written here.

*No difference between input and holding registers. They can be read via function code 0x04.

 

Register Areas for bit by bit access

Address Area

Application

Access

Access Type

Meaning

1 – 3840

Input Bits (Coil)

Read only

Holding/Input*

Values provided by the other RevPi Gate.

16385 – 20224

Output Bits (Coil)

Read/write

Holding

Values supplied to the other RevPi Gate.

*No difference between input and holding registers. They can be read via function code 0x04.

 

Functions

You can access the data area of the gateway component using the following functions:

Function Code

Application

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

Write data 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