Modems in a POWERLOGIC System Modbus RTU to Modbus ASCII February 2002

What’s the Issue? Modbus RTU Modem Communications Modbus ASCII is a time delimited serial protocol a period of 3.5 character times without a character identifies the end of a message (1.5-milliseconds @ 19.2k) Modem Communications character timing of messages transmitted via modems is extremely unpredictable results in communications errors (typically CRC) Modbus ASCII this protocol is more tolerant of time delays between characters in a message (up to 1-second) none of our current products or software support this protocol messages are approximately twice as large as RTU messages 10/27/201910/27/2019

Is there a Solution? Present Solution Install an interface device between each modem to convert from Modbus RTU to Modbus ASCII This maintains a Modbus RTU connection to the devices and to SMS while Modbus ASCII is used between the modems Requires a constant connection 10/27/201910/27/2019

What Does This Look Like? 10/27/201910/27/2019

What If I Need Ethernet? 10/27/201910/27/2019

MUCM Info http://www.niobrara.com/mucm_cut.html 10/27/201910/27/2019

QUCM Info http://www.niobrara.com/ftp/manuals/pdf/mucm_qucm.pdf The QUCM comes out the box in a non-functional state You must load an image into the QUCM prior to configuration Connect PC serial port to QUCM port 1 using NR&D “MM1” cable Copy the ZIP file from the supplied floppy disk and copy to a known directory on you PC Un-ZIP the files From a “command prompt” enter “ZAPREG32 com1:9600,e,8,1 255 -b” A window will open with a “Read / Write Register” interface Enter the desired IP Address in Registers 46 - 49 Enter the desired Subnet Mask in Registers 50 - 53 Enter the desired Default Gateway in Registes 54 - 57 Press “ESC” to exit From the “command prompt” enter “QLOAD 1 QRPCTCP.QCC IPAddressEnteredAbove -a” Now place both switches, next to serial ports, to “RUN” From a “command prompt” enter MEBSW The window above will appear Press “S” to enter the “Setup” screen http://www.niobrara.com/ftp/manuals/pdf/mucm_qucm.pdf 10/27/201910/27/2019