OPERATOR INTERFACE PRODUCTS APPLICATION NOTE

Transcription

1 Page: 1 of 5 Description: The Profibus driver has 2 modes of operation for data transfer: Direct I/O and Packet Transfer. This document explains implementing the Direct I/O method of addressing. An associated spreadsheet, GP_Profibus_Conversion.xls, converts memory addressing between GP-Pro and a Siemens S7-300/400 series PLC. Solution: Additional Resources Needed. The Profibus section of the GP-Pro PB III Device Connections Manual. (V.6.2 or newer.) The file: GP_Profibus_Conversion.xls The *.GSD file shipped with the GP Profibus adapter module. Environment Setup: Configuration in GP-Pro/PB III for Windows 1. Start a new project in GP-Pro/PBIII for Windows with PLC type "Profibus-DP" 2. Under GP Setup Communication settings, choose Direct I/O mode. 3. Specify the LS Starting address where the PLC data will be mapped to in the GP. Also specify the Input and Output area size. Note: The input and output size here are words and should correspond to the number of bytes allocated to the GP in the Profibus-DP master's memory table. 4. Design your application. Use the allocated GP's LS area ONLY. 5. For Direct I/O mode, under "GP Setup Extended Settings", deselect all of the system area. This option is not available in Direct I/O mode. 6. Under "GP Setup Mode settings" ensure that the Reading Area is set to 0. This option is not available in Direct I/O mode.

2 Page: 2 of 5 Hardware Configuration in Siemens Step7 PLC programming software: 1. Ensure that the relevant GSD electronic description file has been copied to the correct directory of your computer. This file is contained in the Fieldbus directory on the GP-Pro/PB III installation disk. Note: Depending on the version of Step 7 you are using the directory names/structure can vary, you should copy this file to the directory under the Step 7 directory where other GSD files are stored. 2. Open Step 7, start a new project and enter the hardware configuration for your S7 3/400 station. Alternatively you can base your project on the example project contained in the Fieldbus directory on the GP-Pro/PB III installation disk. 3. Click "Options Update DDB Files" to inform the Step7 software of the Profibus-DP module parameters. 4. Enter the relevant hardware for your S7 rack. 5. Open the hardware catalog and from "PROFIBUS DP->Additional Field Devices->General, drag the folder "Pro-face 47*/57*/67*" onto your Profibus-DP network if you are using the GP070-PF21 or drag the folder "Pro-face 27*/37*" if you are using the GP377-PF21.

3 Page: 3 of 5 6. Next expand that same "Pro-face x7*/x7 " folder and drag the module "Universal Module" onto the first entry in the slave rack. Take note of the DP slave number of the module. This node number should be set on the Rotary switches of the GP Profibus-DP interface unit. 7. Double click on the newly inserted module to set up the properties of the GP Profibus DP interface unit. 8. The user will be presented with a blank DP Slave properties dialogue box, from the I/O type drop down box, choose input / output type. (Shown below) 9. The input and output size should correspond to those set under GP-Setup/Communications settings, menu from the GP-PRO/PB Editor software

4 Page: 4 of Set up the Input and Output addresses of the Profibus-DP interface unit. The user should make note of both the input start address and output start address, as they will be needed later to correctly perform data transfer. Addressing PLC Variables: For Direct I/O mode the user does not need to make any addition to his PLC program, he needs to be aware of where the GP's memory is mapped in the Master PLC's memory area (point 10 above). He also needs to know where in the GP's LS memory area the Master PLC will be accessing data (point 3 of Configuration in GP-Pro/PB III for Windows). The Siemens S7-300/400 series PLC has byte oriented memory addressing. The driver uses byte swapping is used to convert GP-Pro LS memory values to S7-300 values. Bit addressing is byte swapped also. The spreadsheet utility: GP_Profibus_Conversion.xls simplifies address conversion between GP-Pro software and the S7300/400 PLC program. Enter the GP-Pro and PLC Profibus configuration data from your project in the spreadsheet as shown below: GP-Pro/GP Settings/Communication Settings Proface Profibus Universal Module Settings Start of LS Area 20 Number of words writing to PLC 16 PLC Starting Q Address 20 Number of words read from PLC 16 PLC Starting I Address 40 To use the addressing utility enter a known address in the appropriate outlined box to calculate the equivalent address in the other device. The spreadsheet will calculate a PLC I/O address from a GP-Pro address. Select the appropriate box for either a LS memory word or an LS memory bit. Only enter the address number, not the letters in the prefix. (Example: LS30 is entered as 30) The utility will determine if the PLC register is an input or output and will appropriately address it as a Q or an I in the proper format to use it in the PLC program. To convert a PLC address to a LS address enter the PLC address in the appropriate box. When converting a PLC address it must be entered in the appropriate box for an input or an output. It is up to the user to observe out of range errors. Data entered outside of hardware configured data ranges will not cause an error.

5 Page: 5 of 5 Download your project to the GP. Note: Ensure that you check the box "Send Information GP System Screen" and "Setup Automatic Setup" so that the GP Settings are sent to the GP. GP Interface Unit Configuration: Each node on the Profibus-DP network, is assigned a node number. For the GP interface unit this is set by means of a pair of rotary switches. Note: On the GP070-PF21 the node number is in Decimal 0-99 (1-99 valid) Note: On the GP377-PF21 the node number is in Hexadecimal 0-FF. (1-7E valid) The Terminating resistor should be ON if the GP is the last node on the Profibus-DP network.