7/10/2020 9:57 PM | |
Joined: 9/27/2006 Last visit: 9/24/2024 Posts: 12282 Rating: (2685)
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Hello sara; When the first S7-300 CPUs were produced, they only had an MPI programming port, so they could not use Profibus-DP networks to extend the reach of their I/O modules as they can today. The main rack of a CPU could hold a total of 8 I/O modules, along with a power supply (in slot 1) and the CPU (in slot 2); slot 3 was reserved for a IM module that could extend the number of I/O modules on expansion rack (if there was only 1 rack used, slot 3 was treated as a virtual slot, the first I/O module occupies slot 4). If you needed more modules that could be setup on a single rack, you had to setup expansion racks, each capable of holding up to 8 I/O modules; there could be a maximum of 3 expansion racks attached to one CPU main rack. To give you an overview, please look at the screenshot below, taken from this manual: https://support.industry.siemens.com/cs/ww/en/view/15390415 It shows the main rack (with a CPU in slot 2) and 3 expansion racks (the maximum possible) connected with IM 360 (Send interface in the main rack) and IM 361 (Send/Receive interfaces in the expansion racks) using a special cable only used in that configuration, to extend the CPU's backplane bus to the expansion racks. Each expansion rack holds a maximum of 8 I/O modules. Another option was an IM 365 (a pair of send/receive interfaces limited to 1 m) to setup a two-tiered installation inside a single cabinet). For more details on the different interface modules, look in the appropriate chapter in the S7-300 Module data manual. https://support.industry.siemens.com/cs/ww/en/view/8859629 As I said, today the preferred installation of remote I/O racks uses Profibus/Profinet, with ET 200 M, ET 200S... interface modules and I/O modules. So yes, you can setup a S7-300 rack without IM 365 or IM 360/361. Simply "skip" slot 3 (treat it as virtual) in your rack when you prepare your hardware configuration. Hope this helps, |
Last edited by: dchartier at: 07/11/2020 18:41:00 |
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This contribution was helpful to2 thankful Users |
7/11/2020 5:40 PM | |
Joined: 10/27/2017 Last visit: 11/3/2022 Posts: 9 Rating: (0) |
THANK YOU VERY MUCH FOR YOUR ANSWER |
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