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| 8/26/2009 7:55 AM | |
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Posts: 118 Rating:
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Hi All, I have one doubt that, Why S7-300 CP (340/341) having 15 Pin Port for RS422/RS485 Modules. 9 Pin Port is more than enough for RS 422/485....is in it? |
| 8/26/2009 12:32 PM | |
Joined: 7/17/2008 Last visit: 10/25/2013 Posts: 34 Rating:
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Hi Maha, I think that comes from the ITUT Recommendation V.11 That recommends to use ISO-4903 (DB15) for RS-422aka EIA-422. Regards |
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| 9/4/2009 2:20 AM | |
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Posts: 118 Rating:
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Dear All, I got the very good explanation from the siemens technical support team mentioned below... 1. this are only a theoretical question with no practical impact on our devices. In case you need the CP340/341/440/441 with a RS485/422 interface, you need in any case a 15-Pin Sub-D connector. 2. If you refer the pinout of the RS485 interface of a common CPU, you will see that all pins are used. Refer page 223 (PDF 237) of manual below. S7-200 System Manual http://support.automation.siemens.com/WW/view/en/1109582 3. Did they choose the 15-Pin to avoid misunderstandings regarding other Profibus equipment (like RS485 repeaters which dosent work with PtP-devices), when they developed the modules in the late 90s, is unknown to me. 4. If you want in any case a 9-Pin connector and RS485 is sufficient, and the function range of a S7-200 or S7-1200 is sufficient as well, than take them, since they offer 9-Pin Sub-D ports, do they history common history (S7-200 -> S7-1200 is next generation) S7-200 is capable over MPI Port to communicate ASCII. S7-1200 has a 9-Pin extension communication module. Another option is to take a ET200S where you connect just the wires into a clamp. Contact your local Siemens sales contact. Best regards Your Technical Support for Industry Automation and Drive Technologies Thank You Siemens Technical support team........... |
Last edited by: O_Moderator at: 9/7/2009 8:13 AMName of the Technical support team member deleted |
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