Server User Manual
Table Of Contents
- SDS/SCS/STS/MDC User’s Guide
- Table of Contents
- Preface
- Introduction
- Hardware and Connectivity
- Configuration Methods
- Getting Started
- Using DeviceManager and WebManager
- Network Settings
- Configuring Serial Ports
- Introduction
- Serial Ports
- Serial Port Profiles
- Common Tabs
- Console Management Profile
- TruePort Profile
- TCP Sockets Profile
- UDP Sockets Profile
- Terminal Profile
- User Service Settings
- Printer Profile
- Serial Tunneling Profile
- Virtual Modem Profile
- Control Signal I/O Profile
- Modbus Gateway Profile
- Power Management Profile
- Remote Access (PPP) Profile
- Remote Access (SLIP) Profile
- Custom Application Profile
- Port Buffering
- Advanced
- Configuring Users
- Configuring Security
- Configuring I/O Interfaces
- Configuring Clustering
- Configuring the Option Card
- Configuring the System
- Controlling the RPS, I/O Channels, and IPsec Tunnels
- System Administration
- Introduction
- Managing Configuration Files
- Downloading IOLAN Firmware
- Calibrating I/O
- Setting the IOLAN’s Date and Time
- Rebooting the IOLAN
- Resetting the IOLAN to Factory Defaults
- Resetting the SecurID Node Secret
- Language Support
- Downloading Terminal Definitions
- Resetting Configuration Parameters
- Lost Admin Password
- Applications
- RADIUS and TACACS+
- SSL/TLS Ciphers
- Virtual Modem AT Commands
- Pinouts and Cabling Diagrams
- Setting Jumpers
- I/O Wiring Diagrams
- Utilities
- Accessories
- Troubleshooting
- Introduction
- Hardware Troubleshooting
- Communication Issues
- DeviceManager Problems
- Host Problems
- RADIUS Authentication Problems
- Login Problems
- Problems with Terminals
- Unknown IP Address
- DHCP/BOOTP Problems
- Callback Problems
- Language Problems
- Modem Problems
- PPP Problems
- Printing Problems
- Long Reboot Cycle
- SSL/TLS
- I/O Models
- IPv6 Issues
- Contacting Technical Support
- Glossary
- Index
Modbus I/O Access
278 IOLAN SDS/SCS/STS/MDC User’s Guide, Version 4.0
Modbus TCP Application
If you have a Modbus RTU or Modbus ASCII program, you can access the I/O by connecting to the
IOLAN over the network.
Network
IOLAN
perle
PC running a
Modbus RTU
or ASCII
Application
UID: 15
I/O Digital
Output
Power
Modbus I/O Access
The section defines the function codes and registers you will need to access the I/O through Modbus
TCP, Modbus serial, or Modbus serial/TruePort.
Function Codes
The following function codes are supported by the IOLAN:
z 01 read coils
z 03 read multiple holding registers
z 04 read input registers
z 05 write coil
z 06 write single register
z 08 diagnostics (echo the request)
z 15 force multiple coils
z 16 write multiple registers
There are four Modbus data models:
Discrete Input Not used
Coils Digital Input (DI), Alarm state for DI, Digital Output (DO). All coils
are Boolean values and are 1 byte.
Input Registers (IR) Analog Input (AI), Alarm state for AI. All Input Registers are 2 bytes
long.
Holding Registers Status (R), Control value (R/W or W). Holding Registers with _ENG
registers are 4 bytes long, all other Holding Registers are 2 bytes
long.
All coil/register values are in decimal.