Modbus Tcp/Ip Diagnostic Counters Over Web Hmi; Common Modbus Tcp/Ip Diagnostic Counters; Supported Modbus Function Codes - ABB Remote I/O RIO600 Installation And Commissioning Manual

Section 7
Modbus TCP communication
7.1.4
7.1.5
7.1.6
172

Modbus TCP/IP diagnostic counters over Web HMI

Modbus TCP/IP diagnostic counters can be viewed via the WHMI. These counters
show the sent and received Modbus protocol link frames and Modbus errors.
Table 115: TCP/IP diagnostic counters
Counter Description
Received frames Total amount of received Modbus frames.
Transmitted frames Total amount of transmitted Modbus responses.
Transmitted Exc Total amount of exception responses 1 and 2.
A These exception responses usually reveal configuration errors on the
Modbus client's side.
Transmitted Exc Total amount of exception responses 3.
B These exceptions reveal the application level rejections.
TCP connection status Shows the value "Green" via LED on WHMI, if TCP/IP instance is in use.
A Modbus client has connected to the TCP socket and Modbus TCP
messages are received regularly. In all other cases, it shows the value "Red"
via a LED.
The counters and status are reset when the client makes a TCP socket disconnection
or if the live TCP socket connection times out.

Common Modbus TCP/IP diagnostic counters

Table 116: TCP/IP diagnostic counters (client independent)
Counter Description
CnReject No sockets Amount of connection requests rejected due to unavailable TCP sockets
CnReject Not reg Amount of connection requests rejected since the client is not registered

Supported Modbus function codes

Table 117: Function codes supported by RIO600
Function code Name
01 Read coil status
02 Read digital input status
03 Read holding registers
04 Read input registers
05 Force single coil
06 Preset single register
08 sub Diagnostics: Request query
function code data
00
Description
Reads the status of discrete outputs
Reads the status of discrete inputs
Reads the contents of output registers
Reads the contents of input registers
Sets the status of a discrete output
Sets the value of a holding register
The data in the query data field is returned (looped
back) in the response. The entire response is
identical to the query.
Installation and Commissioning Manual
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RIO600