If you can, choose USB. Both are communication cables. The difference is that the current mainstream computer configuration has a USB port, but not necessarily an RS232 port. If you choose RS232, you have to go with the SUB to RS232 converter.
Why can’t I connect PLC and MICWIN programming software with RS232PPI cable after using NETW NETR instruction?
When using the NETWNETR instruction, the port of the PLC is defined as the master. The PPI network is a token network. Once the primary station has a token, the primary station controls the read and write access rights of the network, and other primary stations cannot access the primary station. All MICROWIN cannot communicate properly with the PLC
USB/PPI cable
USB/PPI cable is suitable for the Siemens S7-200 full range of PLCs. It is a programming cable that provides serial connection and RS485 signal conversion and PPI protocol conversion via USB interface.
The driver control running in the computer simulates the USB interface of the computer into a traditional serial port (commonly known as the COM port), thereby using various existing programming software, communication software, and monitoring software. The working power is taken from the USB port and is not powered by the programming port of the PLC. The two-color LED on the converter box indicates the data transmission and reception status. For industrial sites with high interference and easy to damage the communication port, opto-isolated USB/PPI+ programming cable is selected.
USB/PPI cable characteristics and technical indicators:
1. Support USB/PPI operating system: Windows2000/WindowsXP (WinNT4/95/98/Me/DOS is not supported)
2. Support USB/PPI programming software version: STEP7 Micro/WIN V3.2 and above
3. Fully compatible with USB V1.1 and USB CDC V1.1 specifications
4.USB bus power supply, current consumption is about 50mA
5. Baud rate: 9.6kbps standard baud rate automatically adapts
6. Support UART data format
7. Data bits: 8
8. Stop bits: 1, 2
9. Check digit: odd/even/no parity
10. Support the maximum communication distance of 2KM (9600bps)
11. Only one USB programming cable is supported per PC
USB/PPI cable usage:
The USB/PPI programming cable needs to be installed with the USB device driver. These drivers are included on the CD that ships with the product. For the installation method, please refer to the documentation on the driver CD, which will not be described here.
After the driver installation is completed, the COM port corresponding to the USB/PPI programming cable will appear in the device manager of Windows. Simply select the COM port in the programming software or other application software, and the next use is the same as the traditional RS232. The port programming cable is identical. It should be noted here that the programming cable does not support the “USB” option of the local communication port setting in the programming software.
USB/PPI cable long distance communication:
The maximum communication distance between the USB/PPI programming cable and the PLC can reach 2KM (9600bps). In this case, a 120Ω termination resistor should be connected between the 3rd and 8th pins of the RS485 port of the cable (DB9 Male) to eliminate signal reflection. The PFB-G bus isolator is installed on the PLC side, and the communication line adopts a shielded twisted pair with a cross-sectional area of 0.22 mm2 or more. More than 2000 meters distance can be added to the bus to add RS485 repeater to extend the communication distance.
Siemens PPI cable and USB to 485 have a difference
PPI is a protocol specifically for 200, USB is also a communication protocol, and RS485 is the physical layer definition of the interface.
Siemens wincc connects to the S7-200 through PC Access, using a USB-PPI cable
To import variables into wincc. PC access first establishes a connection with the PLC, then PC access and wincc establish OPC communication, and import the variables of PC access.
How does the Siemens S7-200 CPU222 communicate with the PC/PPI communication cable?
Switch the PLC to “STOP” and connect the communication cable. Open the PLC software, select “Set PC/PG interface” in the lower left corner, open it, select PC/PPI in the list on the left, click the property on the right side, in the property menu that opens, under the PPI option, fill in the address “0” , timeout 1S, advanced PPI and multi-master network to remove the check, the transmission rate is set to 9.6KB / S, the highest address 31, and then switch to “local connection”, according to your communication cable, if it is a USB interface, select SUB If it is a serial port (it is recommended to use Siemens official PC/PPI cable), select COM1 and confirm to exit;
Then select the communication, open the window, check all the baud rates in the lower left corner to search for the PLC you are connected to.
Siemens s7-200, usb-ppi communication steps
Siemens s7-200, usb-ppi communication steps:
1. Install the USB-PPI driver and look at the serial port generated in the device management. Connect the computer with STEP 7 MicroWIN programming software with S7-200PLC and USB/PPI cable.
2. Open the programming software and set the PC/PG interface and select USB.
3. The computer and PLC are connected to upload/download programs via USB/PPI cable.
How to use the usb-ppi cable to establish communication between the computer and the s7-200
Upload/Download S7-200PLC via USB/PPI cable Procedure: Hardware: Computer with STEP7MicroWIN programming software, S7-200PLC, USB/PPI cable.
2. Open the programming software and set the PC/PG interface to select USB3. Connect the computer to the PLC via the USB/PPI cable to upload/download the program.
S7-200 usb-ppi+ communication cannot read PLC information, display unknown number
Showing unknow is a problem with your programming line.
In fact, the software has found the PLC, the site: 1, the baud rate is 9.6kbps.
Your PLC site needs to be set to 1 (manually input or click to display the location of “unknow, 1, .96bps” is automatically set).
Driver for S7-200 USB-PPI programming cable
The interface of Siemens PLC is RS485, so why not use USB-485 cable directly, but use USB-PPI and USB-MPI cable?
1. PPI cable can be converted with a simple RS232-RS485 interface, but cannot meet the high-speed communication of 187.5K.
2. There is a protocol chip in the MPI programming cable, which cannot be converted using a simple RS232-RS485 interface.
3. Many people always bite RS485. In fact, it is two things, one is physical, and PPI and MPI are on the agreement.
What is a PC/PPI programming cable
The S7200 CPU uses RS485, and the COM port of the PC uses RS232. The electrical specifications of the two are not consistent and need to be matched by the intermediate circuit. PC/PPI is indeed a matching cable of RS485/RS232.
PLC Cable 