This article is a guide to connect an Allen Bradley MicroLogix 1100 PLC to Fernhill SCADA.
The Allen Bradley MicroLogix 1100 PLC has two communication channels located on the left side of the unit:
The rest of this page is divided into two topics:
To connect a MicroLogix 1100 PLC to Fernhill SCADA these steps are required:
The MicroLogix 1100 PLC channel 0 can connect directly to a serial port on a PC. The serial port on a PC is usually a 9 pin D-subminiature connector. These cables are suitable to connect the PLC to a computer with a 9 pin D-subminiature connector:
As an alternative you can create your own cable using this wiring:
MicroLogix 1100![]() |
PC![]() | ||
---|---|---|---|
GND | 2 | 5 | GND |
RTS | 3 | 8 | CTS |
RXD | 4 | 3 | TXD |
DCD | 5 | 1 | DCD |
CTS | 6 | 7 | RTS |
TXD | 7 | 2 | RXD |
4 + 6 | DTR + DSR |
Note: All other pins not shown in the above diagram have no connection.
You can use RSLogix 500 to configure the MicroLogix 1100 Serial Port.
Field configuration notes:
There are two methods to configure Fernhill SCADA to communicate with a MicroLogix 1100 PLC:
The default communication settings for Channel 0 on the MicroLogix 1100 are:
Parameter | Value |
---|---|
Baud Rate | 19200 |
Protocol | DF1 Full Duplex |
Error Check | CRC |
Node Address | 1 |
The Fernhill SCADA configuration that corresponds to the defaults for Channel 0 is:
Allen Bradley Serial Port | ||
---|---|---|
Mode | Baud=19200 Parity=N Data=8 Stop=1 | |
Protocol | DF1 Full Duplex | |
ErrorCheck | CRC | |
Allen Bradley PLC | ||
Destination Node | 1 |
Use this table to match the Baud and Parity fields of Channel 0 with the Mode property in Fernhill SCADA:
Baud | Parity | Mode |
---|---|---|
38.4K | NONE | Baud=38400 Parity=N Data=8 Stop=1 |
38.4K | EVEN | Baud=38400 Parity=E Data=8 Stop=1 |
19200 | NONE | Baud=19200 Parity=N Data=8 Stop=1 |
19200 | EVEN | Baud=19200 Parity=E Data=8 Stop=1 |
9600 | NONE | Baud=9600 Parity=N Data=8 Stop=1 |
9600 | EVEN | Baud=9600 Parity=E Data=8 Stop=1 |
For Ethernet communication to work, the PLC must have its own unique IP Address. The MicroLogix 1100 PLC supports three methods to configure the IP Address:
This guide describes manual entry of the IP Address and associated information.
Before you begin, obtain an IP Address from your network administrator. This information is required:
Information | Description |
---|---|
IP Address | The address of the PLC on the network (Required). |
Network Mask | Defines the logical range of addresses on the local network (Required). |
Gateway | Defines address of the network router (Optional). |
Primary Name Server | Defines address of the primary DNS server (Optional). |
Secondary Name Server | Defines address of the secondary DNS server (Optional). |
Note: Enter the values you obtained from your network administrator.
For information about Allen Bradley serial channel configuration.
For information about Allen Bradley PLC Tag configuration.
For background information on serial communications.
For information about the Allen Bradley Driver.
For the meaning of terms used in Fernhill SCADA.