MODBUS

MODBUS protocol

Modicon Communication Bus (MODBUS) is an application-layer protocol for client-server communication between a switch and a network device running MODBUS client software. MODBUS can operate over a serial line and connect a computer to a remote terminal unit (RTU) in supervisory control and data acquisition (SCADA) systems. This setup allows efficient communication among remote computers within SCADA networks.


Note

MODBUS is supported only on standalone IE9300 Rugged series switches.

MODBUS also operates on Ethernet TCP/IP networks. MODBUS TCP connects the switch to devices, such as intelligent electronic devices (IEDs), distributed controllers, substation routers, IP phones, wireless access points, and redundant substation switches. The protocol increases connectivity options across networked devices.

A client, such as an IED or a human-machine interface (HMI) application, can remotely configure and manage devices running MODBUS TCP. The switch functions as the server. The switch encapsulates request and response messages in a MODBUS TCP application data unit (ADU). A client sends these messages to a specific TCP port on the switch.

Cisco catalyst IE9300 MODBUS TCP registers

This document lists the read-only registers for IE9300 switches. MODBUS clients use these registers to communicate with a MODBUS server, the switch. These switches do not support writable registers.

System information registers

The address spaces 0x0800 through 0x0FFF contain read-only system information registers. These 2048 registers are accessible using MODBUS function code 0x03 Read Multiple Registers.

Table 1. System information registers
Address Number of registers Description R/W Format Value
0x0800 64 Product ID R Text
0x0840 64 Software image name R Text
0x0880 64 Software image version R Text
0x08C0 64 Hostname R Text
0x0900 1 Number of Gigabit Ethernet ports R Uint 16
0x0901 1 Number of 10 Gigabit Ethernet ports R Uint 16
0x0902 1 Number of mGig Ethernet ports R Uint 16
0x0903 1 Number of power supplies R Uint 16
0x0904 1 Power supply 1 status R Uint 16

0—Not present

1—Present
0x0905 1 Power supply 2 status R Uint 16

0—Not present

1—Present
0x0906 1 System or sensor ID 0 temperature R Uint 16
0x0907 1 Alarm 1 description R Uint 16
0x0947 2 Alarm 2 description R Uint 16
0x0987 1 Number of alarms R Uint 16
0x0988 1 Alarm 1 status R Uint 16

0—Alarm off

1—Alarm on
0x0989 2 Alarm 2 status R Uint 16

0—Alarm off

1—Alarm on
0x098A 64 Alarm 3 description R Text
0x09CA 64 Alarm 4 description R Text
0x0A0A 1 Alarm 3 status R Uint 16

0—Alarm off

1—Alarm on
0x0A0B 1 Alarm 4 status R Uint 16

0—Alarm off

1—Alarm on

Port information registers

The address spaces 0x1000 through 0x3FFF contain read-only port information registers. These 12,000 registers are accessible using MODBUS function code 0x03 Read Multiple Registers. The registers update each time the switch receives a read request.

This table lists the memory map for all interface registers with 64-bit counters in the address space 0x1000 through 0x2FFF (8,000 registers).

Table 2. Generic port information values
Address Number of registers Description R/W Format
0x1000 64 LAN port 1 name R Text
0x1040 64 LAN port 2 name R Text
0x1080 64 LAN port 3 name R Text
0x10C0 64 LAN port 4 name R Text
0x1100 64 LAN port 5 name R Text
0x1140 64 LAN port 6 name R Text
0x1180 64 LAN port 7 name R Text
0x11C0 64 LAN port 8 name R Text
0x1200 64 LAN port 9 name R Text
0x1240 64 LAN port 10 name R Text
0x1280 64 LAN port 11 name R Text
0x12C0 64 LAN port 12 name R Text
0x1300 64 LAN port 13 name R Text
0x1340 64 LAN port 14 name R Text
0x1380 64 LAN port 15 name R Text
0x13C0 64 LAN port 16 name R Text
0x1400 64 LAN port 17 name R Text
0x1440 64 LAN port 18 name R Text
0x1480 64 LAN port 19 name R Text
0x14C0 64 LAN port 20 name R Text
0x1500 64 LAN port 21 name R Text
0x1540 64 LAN port 22 name R Text
0x1580 64 LAN port 23 name R Text
0x15C0 64 LAN port 24 name R Text
0x1600 64 LAN port 25 name R Text
0x1640 64 LAN port 26 name R Text
0x1680 64 LAN port 27 name R Text
0x16C0 64 LAN port 28 name R Text
0x1700 1 LAN port 1 state R Uint 16
0x1701 1 LAN port 2 state R Uint 16
0x1702 1 LAN port 3 state R Uint 16
0x1703 1 LAN port 4 state R Uint 16
0x1704 1 LAN port 5 state R Uint 16
0x1705 1 LAN port 6 state R Uint 16
0x1706 1 LAN port 7 state R Uint 16
0x1707 1 LAN port 8 state R Uint 16
0x1708 1 LAN port 9 state R Uint 16
0x1709 1 LAN port 10 state R Uint 16
0x170A 1 LAN port 11 state R Uint 16
0x170B 1 LAN port 12 state R Uint 16
0x170C 1 LAN port 13 state R Uint 16
0x170D 1 LAN port 14 state R Uint 16
0x170E 1 LAN port 15 state R Uint 16
0x170F 1 LAN port 16 state R Uint 16
0x1710 1 LAN port 17 state R Uint 16
0x1711 1 LAN port 18 state R Uint 16
0x1712 1 LAN port 19 state R Uint 16
0x1713 1 LAN port 20 state R Uint 16
0x1714 1 LAN port 21 state R Uint 16
0x1715 1 LAN port 22 state R Uint 16
0x1716 1 LAN port 23 state R Uint 16
0x1717 1 LAN port 24 state R Uint 16
0x1718 1 LAN port 25 state R Uint 16
0x1719 1 LAN port 26 state R Uint 16
0x171A 1 LAN port 27 state R Uint 16
0x171B 1 LAN port 28 state R Uint 16
Table 3. Port information values for 64-bit counters
Address Number of registers Description R/W Format
0x171C 4 LAN port 1 statistics—number of packets received R Uint 64
0x1720 4 LAN port 2 statistics—number of packets received R Uint 64
0x1724 4 LAN port 3 statistics—number of packets received R Uint 64
0x1728 4 LAN port 4 statistics—number of packets received R Uint 64
0x172C 4 LAN port 5 statistics—number of packets received R Uint 64
0x1730 4 LAN port 6 statistics—number of packets received R Uint 64
0x1734 4 LAN port 7 statistics—number of packets received R Uint 64
0x1738 4 LAN port 8 statistics—number of packets received R Uint 64
0x173C 4 LAN port 9 statistics—number of packets received R Uint 64
0x1740 4 LAN port 10 statistics—number of packets received R Uint 64
0x1744 4 LAN port 11 statistics—number of packets received R Uint 64
0x1748 4 LAN port 12 statistics—number of packets received R Uint 64
0x174C 4 LAN port 13 statistics—number of packets received R Uint 64
0x1750 4 LAN port 14 statistics—number of packets received R Uint 64
0x1754 4 LAN port 15 statistics—number of packets received R Uint 64
0x1758 4 LAN port 16 statistics—number of packets received R Uint 64
0x175C 4 LAN port 17 statistics—number of packets received R Uint 64
0x1760 4 LAN port 18 statistics—number of packets received R Uint 64
0x1764 4 LAN port 19 statistics—number of packets received R Uint 64
0x1768 4 LAN port 20 statistics—number of packets received R Uint 64
0x176C 4 LAN port 21 statistics—number of packets received R Uint 64
0x1770 4 LAN port 22 statistics—number of packets received R Uint 64
0x1774 4 LAN port 23 statistics—number of packets received R Uint 64
0x1778 4 LAN port 24 statistics—number of packets received R Uint 64
0x177C 4 LAN port 25 statistics—number of packets received R Uint 64
0x1780 4 LAN port 26 statistics—number of packets received R Uint 64
0x1784 4 LAN port 27 statistics—number of packets received R Uint 64
0x1788 4 LAN port 28 statistics—number of packets received R Uint 64
0x178C 4 LAN port 1 statistics—number of packets sent R Uint 64
0x1790 4 LAN port 2 statistics—number of packets sent R Uint 64
0x1794 4 LAN port 3 statistics—number of packets sent R Uint 64
0x1798 4 LAN port 4 statistics—number of packets sent R Uint 64
0x179C 4 LAN port 5 statistics—number of packets sent R Uint 64
0x17A0 4 LAN port 6 statistics—number of packets sent R Uint 64
0x17A4 4 LAN port 7 statistics—number of packets sent R Uint 64
0x17A8 4 LAN port 8 statistics—number of packets sent R Uint 64
0x17AC 4 LAN port 9 statistics—number of packets sent R Uint 64
0x17B0 4 LAN port 10 statistics—number of packets sent R Uint 64
0x17B4 4 LAN port 11 statistics—number of packets sent R Uint 64
0x17B8 4 LAN port 12 statistics—number of packets sent R Uint 64
0x17BC 4 LAN port 13 statistics—number of packets sent R Uint 64
0x17C0 4 LAN port 14 statistics—number of packets sent R Uint 64
0x17C4 4 LAN port 15 statistics—number of packets sent R Uint 64
0x17C8 4 LAN port 16 statistics—number of packets sent R Uint 64
0x17CC 4 LAN port 17 statistics—number of packets sent R Uint 64
0x17D0 4 LAN port 18 statistics—number of packets sent R Uint 64
0x17D4 4 LAN port 19 statistics—number of packets sent R Uint 64
0x17D8 4 LAN port 20 statistics—number of packets sent R Uint 64
0x17DC 4 LAN port 21 statistics—number of packets sent R Uint 64
0x17E0 4 LAN port 22 statistics—number of packets sent R Uint 64
0x17E4 4 LAN port 23 statistics—number of packets sent R Uint 64
0x17E8 4 LAN port 24 statistics—number of packets sent R Uint 64
0x17EC 4 LAN port 25 statistics—number of packets sent R Uint 64
0x17F0 4 LAN port 26 statistics—number of packets sent R Uint 64
0x17F4 4 LAN port 27 statistics—number of packets sent R Uint 64
0x17F8 4 LAN port 28 statistics—number of packets sent R Uint 64
0x17FC 4 LAN port 1 statistics—number of bytes received R Uint 64
0x1800 4 LAN port 2 statistics—number of bytes received R Uint 64
0x1804 4 LAN port 3 statistics—number of bytes received R Uint 64
0x1808 4 LAN port 4 statistics—number of bytes received R Uint 64
0x180C 4 LAN port 5 statistics—number of bytes received R Uint 64
0x1810 4 LAN port 6 statistics—number of bytes received R Uint 64
0x1814 4 LAN port 7 statistics—number of bytes received R Uint 64
0x1818 4 LAN port 8 statistics—number of bytes received R Uint 64
0x181C 4 LAN port 9 statistics—number of bytes received R Uint 64
0x1820 4 LAN port 10 statistics—number of bytes received R Uint 64
0x1824 4 LAN port 11 statistics—number of bytes received R Uint 64
0x1828 4 LAN port 12 statistics—number of bytes received R Uint 64
0x182C 4 LAN port 13 statistics—number of bytes received R Uint 64
0x1830 4 LAN port 14 statistics—number of bytes received R Uint 64
0x1834 4 LAN port 15 statistics—number of bytes received R Uint 64
0x1838 4 LAN port 16 statistics—number of bytes received R Uint 64
0x183C 4 LAN port 17 statistics—number of bytes received R Uint 64
0x1840 4 LAN port 18 statistics—number of bytes received R Uint 64
0x1844 4 LAN port 19 statistics—number of bytes received R Uint 64
0x1848 4 LAN port 20 statistics—number of bytes received R Uint 64
0x184C 4 LAN port 21 statistics—number of bytes received R Uint 64
0x1850 4 LAN port 22 statistics—number of bytes received R Uint 64
0x1854 4 LAN port 23 statistics—number of bytes received R Uint 64
0x1858 4 LAN port 24 statistics—number of bytes received R Uint 64
0x185C 4 LAN port 25 statistics—number of bytes received R Uint 64
0x1860 4 LAN port 26 statistics—number of bytes received R Uint 64
0x1864 4 LAN port 27 statistics—number of bytes received R Uint 64
0x1868 4 LAN port 28 statistics—number of bytes received R Uint 64
0x186C 4 LAN port 1 statistics—number of bytes sent R Uint 64
0x1870 4 LAN port 2 statistics—number of bytes sent R Uint 64
0x1874 4 LAN port 3 statistics—number of bytes sent R Uint 64
0x1878 4 LAN port 4 statistics—number of bytes sent R Uint 64
0x187C 4 LAN port 5 statistics—number of bytes sent R Uint 64
0x1880 4 LAN port 6 statistics—number of bytes sent R Uint 64
0x1884 4 LAN port 7 statistics—number of bytes sent R Uint 64
0x1888 4 LAN port 8 statistics—number of bytes sent R Uint 64
0x188C 4 LAN port 9 statistics—number of bytes sent R Uint 64
0x1890 4 LAN port 10 statistics—number of bytes sent R Uint 64
0x1894 4 LAN port 11 statistics—number of bytes sent R Uint 64
0x1898 4 LAN port 12 statistics—number of bytes sent R Uint 64
0x189C 4 LAN port 13 statistics—number of bytes sent R Uint 64
0x18A0 4 LAN port 14 statistics—number of bytes sent R Uint 64
0x18A4 4 LAN port 15 statistics—number of bytes sent R Uint 64
0x18A8 4 LAN port 16 statistics—number of bytes sent R Uint 64
0x18AC 4 LAN port 17 statistics—number of bytes sent R Uint 64
0x18B0 4 LAN port 18 statistics—number of bytes sent R Uint 64
0x18B4 4 LAN port 19 statistics—number of bytes sent R Uint 64
0x18B8 4 LAN port 20 statistics—number of bytes sent R Uint 64
0x18BC 4 LAN port 21 statistics—number of bytes sent R Uint 64
0x18C0 4 LAN port 22 statistics—number of bytes sent R Uint 64
0x18C4 4 LAN port 23 statistics—number of bytes sent R Uint 64
0x18C8 4 LAN port 24 statistics—number of bytes sent R Uint 64
0x18CC 4 LAN port 25 statistics—number of bytes sent R Uint 64
0x18D0 4 LAN port 26 statistics—number of bytes sent R Uint 64
0x18D4 4 LAN port 27 statistics—number of bytes sent R Uint 64
0x18D8 4 LAN port 28 statistics—number of bytes sent R Uint 64
Table 4. Port information values for 32-bit counters
Address Number of registers Description R/W Format
0x18DC 2 LAN port 1 statistics—number of packets received R Uint 32
0x18DE 2 LAN port 2 statistics—number of packets received R Uint 32
0x18E0 2 LAN port 3 statistics—number of packets received R Uint 32
0x18E2 2 LAN port 4 statistics—number of packets received R Uint 32
0x18E4 2 LAN port 5 statistics—number of packets received R Uint 32
0x18E6 2 LAN port 6 statistics—number of packets received R Uint 32
0x18E8 2 LAN port 7 statistics—number of packets received R Uint 32
0x18EA 2 LAN port 8 statistics—number of packets received R Uint 32
0x18EC 2 LAN port 9 statistics—number of packets received R Uint 32
0x18EE 2 LAN port 10 statistics—number of packets received R Uint 32
0x18F0 2 LAN port 11 statistics—number of packets received R Uint 32
0x18F2 2 LAN port 12 statistics—number of packets received R Uint 32
0x18F4 2 LAN port 13 statistics—number of packets received R Uint 32
0x18F6 2 LAN port 14 statistics—number of packets received R Uint 32
0x18F8 2 LAN port 15 statistics—number of packets received R Uint 32
0x18FA 2 LAN port 16 statistics—number of packets received R Uint 32
0x18FC 2 LAN port 17 statistics—number of packets received R Uint 32
0x18FE 2 LAN port 18 statistics—number of packets received R Uint 32
0x1900 2 LAN port 19 statistics—number of packets received R Uint 32
0x1902 2 LAN port 20 statistics—number of packets received R Uint 32
0x1904 2 LAN port 21 statistics—number of packets received R Uint 32
0x1906 2 LAN port 22 statistics—number of packets received R Uint 32
0x1908 2 LAN port 23 statistics—number of packets received R Uint 32
0x190A 2 LAN port 24 statistics—number of packets received R Uint 32
0x190C 2 LAN port 25 statistics—number of packets received R Uint 32
0x190E 2 LAN port 26 statistics—number of packets received R Uint 32
0x1910 2 LAN port 27 statistics—number of packets received R Uint 32
0x1912 2 LAN port 28 statistics—number of packets received R Uint 32
0x1914 2 LAN port 1 statistics—number of packets sent R Uint 32
0x1916 2 LAN port 2 statistics—number of packets sent R Uint 32
0x1918 2 LAN port 3 statistics—number of packets sent R Uint 32
0x191A 2 LAN port 4 statistics—number of packets sent R Uint 32
0x191C 2 LAN port 5 statistics—number of packets sent R Uint 32
0x191E 2 LAN port 6 statistics—number of packets sent R Uint 32
0x1920 2 LAN port 7 statistics—number of packets sent R Uint 32
0x1922 2 LAN port 8 statistics—number of packets sent R Uint 32
0x1924 2 LAN port 9 statistics—number of packets sent R Uint 32
0x1926 2 LAN port 10 statistics—number of packets sent R Uint 32
0x1928 2 LAN port 11 statistics—number of packets sent R Uint 32
0x192A 2 LAN port 12 statistics—number of packets sent R Uint 32
0x192C 2 LAN port 13 statistics—number of packets sent R Uint 32
0x192E 2 LAN port 14 statistics—number of packets sent R Uint 32
0x1930 2 LAN port 15 statistics—number of packets sent R Uint 32
0x1932 2 LAN port 16 statistics—number of packets sent R Uint 32
0x1934 2 LAN port 17 statistics—number of packets sent R Uint 32
0x1936 2 LAN port 18 statistics—number of packets sent R Uint 32
0x1938 2 LAN port 19 statistics—number of packets sent R Uint 32
0x193A 2 LAN port 20 statistics—number of packets sent R Uint 32
0x193C 2 LAN port 21 statistics—number of packets sent R Uint 32
0x193E 2 LAN port 22 statistics—number of packets sent R Uint 32
0x1940 2 LAN port 23 statistics—number of packets sent R Uint 32
0x1942 2 LAN port 24 statistics—number of packets sent R Uint 32
0x1944 2 LAN port 25 statistics—number of packets sent R Uint 32
0x1946 2 LAN port 26 statistics—number of packets sent R Uint 32
0x1948 2 LAN port 27 statistics—number of packets sent R Uint 32
0x194A 2 LAN port 28 statistics—number of packets sent R Uint 32
0x194C 2 LAN port 1 statistics—number of bytes received R Uint 32
0x194E 2 LAN port 2 statistics—number of bytes received R Uint 32
0x1950 2 LAN port 3 statistics—number of bytes received R Uint 32
0x1952 2 LAN port 4 statistics—number of bytes received R Uint 32
0x1954 2 LAN port 5 statistics—number of bytes received R Uint 32
0x1956 2 LAN port 6 statistics—number of bytes received R Uint 32
0x1958 2 LAN port 7 statistics—number of bytes received R Uint 32
0x195A 2 LAN port 8 statistics—number of bytes received R Uint 32
0x195C 2 LAN port 9 statistics—number of bytes received R Uint 32
0x195E 2 LAN port 10 statistics—number of bytes received R Uint 32
0x1960 2 LAN port 11 statistics—number of bytes received R Uint 32
0x1962 2 LAN port 12 statistics—number of bytes received R Uint 32
0x1964 2 LAN port 13 statistics—number of bytes received R Uint 32
0x1966 2 LAN port 14 statistics—number of bytes received R Uint 32
0x1968 2 LAN port 15 statistics—number of bytes received R Uint 32
0x196A 2 LAN port 16 statistics—number of bytes received R Uint 32
0x196C 2 LAN port 17 statistics—number of bytes received R Uint 32
0x196E 2 LAN port 18 statistics—number of bytes received R Uint 32
0x1970 2 LAN port 19 statistics—number of bytes received R Uint 32
0x1972 2 LAN port 20 statistics—number of bytes received R Uint 32
0x1974 2 LAN port 21 statistics—number of bytes received R Uint 32
0x1976 2 LAN port 22 statistics—number of bytes received R Uint 32
0x1978 2 LAN port 23 statistics—number of bytes received R Uint 32
0x197A 2 LAN port 24 statistics—number of bytes received R Uint 32
0x197C 2 LAN port 25 statistics—number of bytes received R Uint 32
0x197E 2 LAN port 26 statistics—number of bytes received R Uint 32
0x1980 2 LAN port 27 statistics—number of bytes received R Uint 32
0x1982 2 LAN port 28 statistics—number of bytes received R Uint 32
0x1984 2 LAN port 1 statistics—number of bytes sent R Uint 32
0x1986 2 LAN port 2 statistics—number of bytes sent R Uint 32
0x1988 2 LAN port 3 statistics—number of bytes sent R Uint 32
0x198A 2 LAN port 4 statistics—number of bytes sent R Uint 32
0x198C 2 LAN port 5 statistics—number of bytes sent R Uint 32
0x198E 2 LAN port 6 statistics—number of bytes sent R Uint 32
0x1990 2 LAN port 7 statistics—number of bytes sent R Uint 32
0x1992 2 LAN port 8 statistics—number of bytes sent R Uint 32
0x1994 2 LAN port 9 statistics—number of bytes sent R Uint 32
0x1996 2 LAN port 10 statistics—number of bytes sent R Uint 32
0x1998 2 LAN port 11 statistics—number of bytes sent R Uint 32
0x199A 2 LAN port 12 statistics—number of bytes sent R Uint 32
0x199C 2 LAN port 13 statistics—number of bytes sent R Uint 32
0x199E 2 LAN port 14 statistics—number of bytes sent R Uint 32
0x19A0 2 LAN port 15 statistics—number of bytes sent R Uint 32
0x19A2 2 LAN port 16 statistics—number of bytes sent R Uint 32
0x19A4 2 LAN port 17 statistics—number of bytes sent R Uint 32
0x19A6 2 LAN port 18 statistics—number of bytes sent R Uint 32
0x19A8 2 LAN port 19 statistics—number of bytes sent R Uint 32
0x19AA 2 LAN port 20 statistics—number of bytes sent R Uint 32
0x19AC 2 LAN port 21 statistics—number of bytes sent R Uint 32
0x19AE 2 LAN port 22 statistics—number of bytes sent R Uint 32
0x19B0 2 LAN port 23 statistics—number of bytes sent R Uint 32
0x19B2 2 LAN port 24 statistics—number of bytes sent R Uint 32
0x19B4 2 LAN port 25 statistics—number of bytes sent R Uint 32
0x19B6 2 LAN port 26 statistics—number of bytes sent R Uint 32
0x19B8 2 LAN port 27 statistics—number of bytes sent R Uint 32
0x19BA 2 LAN port 28 statistics—number of bytes sent R Uint 32

Interpreting the port state value

This section provides information for determining the port state.

The upper byte indicates the interface state. The lower byte indicates the line protocol state. These values help determine the port state.

Address

Description

Value

0x1700 to 0x171B

Port state details

Upper byte:

  • 0x0: Interface down

  • 0x1: Interface going down

  • 0x2: Interface initializing

  • 0x3: Interface coming up

  • 0x4: Interface up and running

  • 0x5: Interface reset by user

  • 0x6: Interface shut down by user

  • 0x7: Interface being deleted

Lower byte:

  • 0x0: Line protocol state down

  • 0x1: Line protocol state up

Configure the MODBUS TCP server

Configure the MODBUS TCP server to enable communication between MODBUS clients and the switch. This procedure includes enabling the server, setting the TCP port, and configuring connection limits.

The MODBUS TCP server listens for MODBUS client requests on TCP port 502 by default. Port 502 is enabled when the MODBUS server starts. If you configure a different port, the server uses the specified port instead.


Note

MODBUS is supported only on standalone Cisco Catalyst IE9300 Rugged Series Switches.

Before you begin

If security services are enabled, ensure the switch TCP port is not blocked. To enhance security, configure an ACL to permit traffic from specific clients. Alternatively, configure QoS to rate-limit traffic.

Procedure

Step 1

Use configure terminal command to enter global configuration mode.

Example:

Device#configure terminal

Step 2

Use the scada modbus tcp server command to enable the MODBUS TCP server. To disable the server and restore its default settings, use the no scada modbus tcp server command.

Example:

Device(config)#scada modbus tcp server

Switch(config)#scada modbus tcp server
WARNING: Starting Modbus TCP server is a security risk. Please understand the security issues involved before proceeding further. 
Do you still want to start the server? [yes/no]: yes

Note

 

The system displays a security risk warning and prompts for confirmation.

Enter yes to confirm and start the server.

Step 3

(Optional) Use the scada modbus tcp server port tcp-port-number command to set the TCP port for client messages.

Example:

Device(config)#scada modbus tcp server port 502

The range for tcp-port-number is 1 to 65535. The default is 502.

Step 4

(Optional) Use the scada modbus tcp server connection connection-requests to set the number of simultaneous connection requests.

Example:

Device(config)#scada modbus tcp server connection 1

The range for connection-requests is 1 to 5. The default is 1.

Step 5

Use the end command to return to privileged EXEC mode.

Example:

Device(config)#end

MODBUS display commands

These commands display MODBUS TCP server details.

Table 5. Show scada modbus tcp server commands

Command

Purpose

show scada modbus tcp servers

Displays server information and statistics

show scada modbus tcp server connections

Displays information and statistics for each client connection

clear scada modbus tcp server statistics

Clears MODBUS server statistics, including statistics for each client connection
Output: show scada modbus tcp server command output

Switch# show scada modbus tcp server
Summary: enabled, running, process id 142
Conn Stats: listening on port 801, 4 max simultaneous connections
0 current client connections
0 total accepted connections, 0 accept connection errors
0 closed connections, 0 close connection errors
Send Stats: 0 tcp msgs sent, 0 tcp bytes sent, 0 tcp errors
0 responses sent, 0 exceptions sent, 0 send errors
Recv Stats: 0 tcp msgs received, 0 tcp bytes received, 0 tcp errors
0 requests received, 0 receive errors

Feature history

This table lists the release information for the features described in this guide. Unless otherwise noted, features are available in all subsequent releases.

Release

Feature

Feature information

Cisco IOS XE Dublin 17.12.1

MODBUS

Cisco Catalyst IE9300 Rugged Series Switches support the Modicon Communication Bus (MODBUS) starting with this release.