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jqleandro

Micrologix 1100 and modbus comunication mini port details

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Hi guys! Well i have a anoying problem, whith micrologix 1100 the problem is, i have on machine whith use micrologix 1100 and 6 powerflex 4m in a modbus rtu communication, direct in the mini din port( no NC converter). At here ok the communication work like heaven, but now i have to put one another slave, what is a another plc (XGB-DR20E lsis LG automation line), micrologix is using pin 2,4,7, (mini din port) when i put XGB in the network it fall, when i remove it back. That is my question how i make it work, i dont get Micrologix 1100 have RS 485 and 232 in that mini port right? And if i was control 6 inverters it have to be Rs485 so why i put another slave it wont work? I alread swap cable try link micrologix and XGB direct but nothing work, the configuration are the same, the distance bethew are no longer than 10meters. Some body can brigh me some light? I confuse whith mini din port pinout and cant find nothing in manual or internet.

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Polarity of the TX and RX terminals on the new device? Termination resistors on both ends of the network?

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Polarity of Tx and Rx? I invert the cable no success. The original network is a crappy i will remake that, but resistor are not the problem I put 2 plc at less than 20cm and wont work.

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Here is the pinout... 8pin_pinoutRS485.pdf 1763_NC01_cable_pin_out__Answer_ID_34450.doc Edited by Mickey

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Thanks Mickey, but is that one thing is make me confuse. In the actual instalation(micrologix+6 powerflex4m), the pins used are 2,4,7, and this make me confuse a lot. Because they are pin of RS232 right? I read in some manual, the pins 1,2,8 are for DH485 and if used in other way can damage the min Din port. I am realy confuse in this case. Maybe this question help me a litle bit. 1 - How the micrologix know if it is using the RS232 or RS485 in modbus configurarion?Is whith pins? Or it use the same pins(2,4,7, for Rs232 and RS485) and have some software configuration?(i sow in RSLogix500, Modbus configuration "No handshanking 485") 2 - If pins 1,2,8 are Rs485 and 2,4,7 are RS232, how i can control those 6 powerflex 4m? Edited by jqleandro

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We have only use the NC01 breakout cable. It isolates the RS485 pins plus povides a termination resistor. The communication port of the Powerfleex 4M expects the voltage levels of RS485 (common to 5VDC). If you use any othe pins from the Microogix communication port (RS 232 is =12 VDC to +12 VDC) you will eventually destroy either the Micrologix or Powerflex ports. Please stop trying to use the other pins. We have used the NC01 breakout with the Powerflex 4M in conjunction with other devicees expecting an RS485 compatible signal with success. I'll provide more information tomorrow when I am able to use diagrams at work.

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Hello b_carlton Well i not tryng use anithing this is what already have there. (Is not my project). I dont have and cant buy NC01 now, this is not a option, what i need to know is how the powerflex are comunicating whith success whith pins 2,4 and 7 and if they are RS485 or 232 just this. And how i put another slave whith this, is just that. Another question NC01 is a converter? RS232 for RS485 or just a isolator? About voltage i measure and is 9V.

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The NC01 is just a breakout - no conversion. 8 - Pin 1 ---------- 4 'B' 2 ---------- 3 'Common' 8 ---------- 5 'A' These are the RS485 connections. I don't know how it would work with the RS232 connections. I haven't (and wouldn't) try them. I would guess that the only way you can get this to work is to change to the RS485 pins and re-wire as necessary. Edited by b_carlton

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Pins 2,4,7 on the ML1100 is RS232 See 8 pin pniout on my post above.

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I get, your guys are probaly right the original network of this machine is RS232. I dont know powerflex 4m acept this eletrical type of network, I thought was just Rs485. This explain why the network is in Star Topology and no Daisy Chain.Maybe one slave respond at time, in other words, just one to one communication at time. Explain why all powerflex have 3 pins in your RJ45 conector connected to Micrologix. But dont explain why the network fall when one slave is desconected. Anyway i will remake this network whith pins that Mickey say. I have 2 more question, u guys know the pinout of RJ45 of powerflex4m? And when i use Rs485 whith micrologix i need to use "no handshaking Rs485" in toolbox or just use "no handshaking"

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Here is the pinout. It looks like RS485 to me. I have never used a PowerFlex4m. My post was about the pins used on the ML1100, I am not saying what kind of network you are using to communicate with your PowerFlex's Maybe if you tell the forum more about the wiring between the ML1100 and the PowerFlex's it may help someone help you. pinoutpowerflexrj45.pdf

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Use the "No Handshaking RS485" option.

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