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How to configure CR300 as ModBus slave?

alexandrecf80 Aug 23, 2019 08:34 AM


How do I configure the CR300 as a ModBUs slave device for using with direct connection and RS-232 interface? I'll have an external application as a ModBus master.

I'm not finding this option in the Short Cut application (Control item) as in some tutorials for the CR1000 device. Do I need a special OS version? I'm using OS 6.01.

Best regards,


GaryTRoberts Aug 26, 2019 09:37 AM

Yes. You need a newer version of the logger operating system for the CR1000. The current/latest released version is 32.03. The ModusSlave() instruction will get you what you are looking for.

alexandrecf80 Aug 26, 2019 02:21 PM

Hi Gary.

Thanks for your reply.

I'm using the CR300, not the CR1000.  As seen in https://www.campbellsci.com/downloads/cr300-series-os, the last version of the OS for CR300 is 9.02.

It's the same for CR300? The ModbusSlave() instruction is available in version 9.02?

Best regards,


GaryTRoberts Aug 27, 2019 03:02 PM

Yes, ModBusSlave() is in OS 09.02. It has been in the CR300 OS for a long time. Since at least version 3.0. You will have to program it by hand. ModBusSlave() is not in ShortCut for the CR300.

alexandrecf80 Aug 31, 2019 02:31 PM

Hi, Gary.

I successfully programmed the Modbus Slave mode by hand in CR300 using CRBasic Editor and the application note "Using Campbell Scientific Dataloggers as Modbus Slave Devices in a SCADA Network".

Thanks for your help!

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