# Communication connection types of Simatic PLC with other hardware **URL:** \ **Category:** Siemens\ **Created:** [February 12, 2019, 2:37pm UTC](https://forumautomation.com/t/communication-connection-types-of-simatic-plc-with-other-hardware/5910 "2019-02-12T14:37:04Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![sivaranjith](https://forumautomation.com/letter_avatar_proxy/v4/letter/s/ba9def/32.png) [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Post date:** [February 12, 2019, 2:37pm UTC](https://forumautomation.com/t/communication-connection-types-of-simatic-plc-with-other-hardware/5910/1 "2019-02-12T14:37:04Z")
S7-200 CPUs can be configured to work in network communications. A personal computer with the Step7-Micro / Win32 program or a programming device SIMATIC PG740 can be used as a “master device”. The types of network communication that can be implemented are as follows: ### Single Master: A single master device connected to one or several slave device as shown in the image below: ![sima1](https://cdn.forumautomation.com/original/2X/7/721a748039f1a1c172d9270a00f2b847c55bd87d.png) ### Multiple Master: A single master device connected to one or more slave devices or other master devices as shown in the following image. ![sima2](https://cdn.forumautomation.com/original/2X/7/7a6e80f6845e8b47e69a226a9f948c28004b54ef.png) ### Using a 10 bit modem: A single master device is connected to one or more other slave devices or other master devices using a 10-bit modem. Only one connection with the S7-200 CPU can be made using this 10-bit modem. For that you need the following components: - One [**S7-200**](https://w3.siemens.com/mcms/programmable-logic-controller/en/simatic-s7-controller/s7-200/pages/default.aspx) CPU is compatible with a 10-bit modem, namely the model: CPU221, CPU222, CPU224 and CPU226. Other CPUs do not support the use of the 10-bit format. - Standard [**RS232**](https://forumautomation.com/t/serial-communication-and-rs-232/3619) cable for connecting the Personal Computer to a 10-bit full-duplex local modem - PC / PPI cable (5-switch) to connect the remote modem to the CPU. - Connect 9 pins to 25 pins if needed. The following figure shows the use of 10-bit modems in a network with PPI 5-switches: ![sima%2010bit](https://cdn.forumautomation.com/original/2X/b/b7320caacf7a230b621363b9a582c630365b88cb.png) ### Using an 11-bit modem: A single master device is connected to one or more slave devices or other master devices using an 11-bit modem. Most modems on the market don’t support the use of the 11 Bit format. Depending on the connection of the personal computer to one or more S7-200 CPUs and/or connections to the network, the following components are needed. - Standard RS232 cable for connecting Personal Computers to 11-bit full-duplex Modems - PC / PPI cable (4 or 5-switch) to connect the remote modem to the CPU. If a PC / PPI 4-switch cable is used then a null modem adapter is required. - If a connection is needed with multiple CPUs in the network, a network adapter is needed (PROFIBUS from Siemens) The following figure shows the use of an 11-bit modem in a network : ![sima11bit](https://cdn.forumautomation.com/original/2X/d/dd3e7c512908f94b48afcc39f2bdfb9220abea36.png) ### Master Network: The following image shows a configuration of a personal computer that is connected to several S7-200 CPUs. Step7 Micro / Win32 is designed to communicate with one CPU at a time, but the computer can access any CPU on the network alternately. In this picture, the CPU can be a master or slave while the TD200 is a master. ![Simamas](https://cdn.forumautomation.com/original/2X/4/4629fd65ed637cc3e37af7148e1e7e8005857fb7.png) ### Network Repeaters: This network repeater is needed if the distance between the CPUs is far apart if you want to add a CPU, or to isolate a network from another network. [**PROFIBUS**](https://forumautomation.com/t/what-is-profibus-communication/5544) can connect 32 components in a network within a distance of up to 1200m. A repeater will allow the addition of 32 more components and an additional distance of 1200m at the 9600 [**Baud rate**](https://forumautomation.com/t/what-is-baud-rate-and-bits-per-second/3495). In the network, 9 repeaters can be used with a network length of no more than 9600m. Each repeater will provide Bias and Termination for each network segment. ![sima%20netw](https://cdn.forumautomation.com/original/2X/c/c6add8b0b8001c6d9b1cc73eed4a7251c17996ee.png)