# Problem with Node-red- Modbus / S7 node **URL:** \ **Category:** General\ **Created:** [10 July 2018 09:29 UTC](https://discourse.nodered.org/t/problem-with-node-red-modbus-s7-node/1480 "2018-07-10T09:29:53Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![somavaram](https://avatars.discourse-cdn.com/v4/letter/s/977dab/32.png) [@somavaram](https://discourse.nodered.org/u/somavaram)\ **Post date:** [10 July 2018 09:29 UTC](https://discourse.nodered.org/t/problem-with-node-red-modbus-s7-node/1480/1 "2018-07-10T09:29:53Z")
Hi Everyone, 1. I am presently working on Siemens S7-1500 PLC. I configured the PLC as modbus client. Now, I am trying to read the holding registers using Modbus read. But unfortunately, I am unable to establish the connection, The status on the node shows "Initialize" changes to "Error FSM not ready to read at state INIT" and then reconnecting. I have no clue how to solve this issue please help. 2. I have also tried using node S7 node to connect the PLC but as soon as I enter the IP address and deploy it the status on the node changes to disconnect. Please give your valuable suggestions. Regards, Somavaram ![modbus_error](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/6/6038ada4d2bebf9b743276e16a9ec84a90bb133d.JPG) ---
**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\ **Post date:** [10 July 2018 09:42 UTC](https://discourse.nodered.org/t/problem-with-node-red-modbus-s7-node/1480/2 "2018-07-10T09:42:56Z")
I suggest you start by googling for Error FSM not ready to read at state INIT That shows a number of hits that may be relevant to your problem. ---
**Author:** ![Cristiano](https://avatars.discourse-cdn.com/v4/letter/c/b5e925/32.png) [@Cristiano](https://discourse.nodered.org/u/Cristiano)\ **Post date:** [11 July 2018 00:24 UTC](https://discourse.nodered.org/t/problem-with-node-red-modbus-s7-node/1480/3 "2018-07-11T00:24:13Z")
hello 😃 I'm using s7 node and work really nice. in the PLC you have "Put / Get ..." active ? Is "DB" configured without optimization? the plc port must also be configured on the S7 node ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/a/a26337c316b3814b58a1c3bfab821dfa0ac06de3.png) ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/b/b1903f76bce9f1038f1ceb5315b81b035e947f4e.png) but this all depends on the firmware version of your CPU, in the most extreme cases that happened to me, I added a PC in the network ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/4/4fba4acb2e1ec4e5f65a39b11d26783cc0fc8833.png) Node-Red side: ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/8/8aec3fc8b7c25f6edb578ef0bc25c47bc9decafc.png) configure your plc ip and rack , slot..... how to read ? ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/3/3c13831e30ccdf867aea3106122dd1aa2add8d7b.png) DB number, DB offset ---
**Author:** ![somavaram](https://avatars.discourse-cdn.com/v4/letter/s/977dab/32.png) [@somavaram](https://discourse.nodered.org/u/somavaram)\ **Post date:** [11 July 2018 07:48 UTC](https://discourse.nodered.org/t/problem-with-node-red-modbus-s7-node/1480/4 "2018-07-11T07:48:07Z")
Hi @Cristiano, Thanks a lot for the pics. I am new to TIA Portal siemens. I configured the the PLC but I have not configured the Node-red PC. What does the PC Station do ? What PC systems should I use for the desktop? How do I configure it? I am currenty using CPU 1512SP F-1 firmvare V2.1 Regards, Somavaram ---
**Author:** ![Cristiano](https://avatars.discourse-cdn.com/v4/letter/c/b5e925/32.png) [@Cristiano](https://discourse.nodered.org/u/Cristiano)\ **Post date:** [11 July 2018 23:04 UTC](https://discourse.nodered.org/t/problem-with-node-red-modbus-s7-node/1480/5 "2018-07-11T23:04:02Z")
Hello adding the station is not mandatory, but I used it in strange cases with the v1.x firmware. With firmware v2 I think it works without the station, but I'll leave the print below 1 step: ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/1/1ad0b3415fde6afc51de0fcbc889c20306c0df1e.png) 2step: add network board ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/5/5acf464322f0d7ce1367a0371bf7d1c5419cf631.png) 3step: drag n drop connection ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/1/142ca9b84509f3c84837e535e3cbdac24f78f8a6.png) Are you using the cpu simulator? or are you testing with a physical cpu? ---
**Author:** ![somavaram](https://avatars.discourse-cdn.com/v4/letter/s/977dab/32.png) [@somavaram](https://discourse.nodered.org/u/somavaram)\ **Post date:** [12 July 2018 08:51 UTC](https://discourse.nodered.org/t/problem-with-node-red-modbus-s7-node/1480/6 "2018-07-12T08:51:36Z")
Hi @Cristiano, Thank you again for the pics. I am testing it on a physical device. Didn't work after using a pc station as well. Regards, Somavaram ---
**Author:** ![machadotiago](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/machadotiago/32/23776_2.png) [@machadotiago](https://discourse.nodered.org/u/machadotiago)\ **Post date:** [5 September 2018 20:07 UTC](https://discourse.nodered.org/t/problem-with-node-red-modbus-s7-node/1480/7 "2018-09-05T20:07:46Z")
Hi @somavaram have you tried to ping your PLC from the machine where you are running Node-RED? Does it ping? If yes what happens if you only configure the IP address and rack and let the DB variables table empty? ---
**Author:** ![ovibro](https://avatars.discourse-cdn.com/v4/letter/o/74df32/32.png) [@ovibro](https://discourse.nodered.org/u/ovibro)\ **Post date:** [24 April 2019 13:23 UTC](https://discourse.nodered.org/t/problem-with-node-red-modbus-s7-node/1480/8 "2019-04-24T13:23:17Z")
You are a lifesaver