Sierra 780S Series Flat-Trak User manual

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This Quick Install Guide is applicable for models: 620S, 620S-BT, 640S, 760S, 780S, and 780S-UHP.
A copy of this Quick Install Guide, the 600/700 Series Modbus manual and the 620S, 640S, and 780S product manuals are
also included on the digital communication information CD included in your shipment. This information is also available for
download.
Connecting to a Modbus Network
You will need the following to connect Modbus to your device:
1. A Modbus equipped 600/700 Series flow meter
2. A PC equipped with a 2-wire RS-485 interface card or USB to RS-485 adapter.
3. A 2-wire RS-485 network with an end of line terminator with pull up and pull down resistors. This becomes
more critical when you have more slaves, longer wires, and higher baud rates. See 600/700 Series Modbus
Manual, Chapter 1.
4. A HyperTerminal or another terminal program to access the boot loader to set the ID#, Baud rate, Parity, and
Tx delay.
Note: The HyperTerminal has been removed from Windows 7. Go to http://helpdeskgeek.com/windows-
7/windows-7-hypertermnal for alternative and information.
5. Power supply to power 600/700 Series instrument, 24VDC @ 625 MA, or 15 VDC (620S-BT only)
Installation Steps
1. Connect the flow meter to the A and B RS-485 network connections.
2. Start the HyperTerminal (Baud 9600, bits 8, Parity N, Stop 1).
3. Power-up the meter. Pin 1 +24 VDC and Pin 2– 24 VDC.
4. Press Enter on your PC within 2 seconds of powering up the 600/700 Series to start the boot loader.
5. Setup meter ID (1 to 247) and the other COM settings. See Set Up instructions in the 600/700 Series Modbus
Manual, Chapter 2.
6. Quit the boot loader and exit the HyperTerminal. Start your Modbus application.
7. All the available registers are listed below.
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Commands Implemented
Function Sub Function Description
0x03 N/A Read holding registers
0x06 N/A Write single holding register
0x08 Diagnostics
0x00 Return query data
0x01 Restart communications option
0x04 Force listen only mode
0x0A Clear counters
0x0B Return bus message count
0x0C Return bus communication error count
0x0D Return bus exception error count
0x0E Return slave message count
0x0F Return slave no response count
0x10 Return slave NAK count
0x11 Return slave busy count
0x12 Return bus character overrun count
0x14 Clear overrun counter and flag
Holding Registers
Register Read Write Type No.
Registers
40001 Actual flow - low word 32 bit float 2
40002 Actual flow - high word
40003 Totalizer - low word 32 bits int 2
40004 Totalizer - high word
40005 User full scale User full scale 16 bits int 1
40006 Factory full scale 16 bits int 1
40007 K factor K factor 16 bits int 1
40008 Dummy (reads $0001) Reset totalizer 16 bits int 1
40009 Calibration - high word * 32 bits Int 2
40010 Calibration - low word *
40011 Flow unit - char 1,2 String 3
40012 Flow unit - char 3,4
40013 Flow unit - char 5,6
40014 Totalizer unit- char 1,2 String 2
40015 Totalizer unit- char 3,4
40016 Serial number – char 1,2 String 6
40017 Serial number – char 3,4
40018 Serial number – char 5,6
40019 Serial number – char 7,8
40020 Serial number – char 9,10
40021 Serial number – char 11,12
40022 Tag number - char 1,2 String 5
40023 Tag number - char 3,4
40024 Tag number - char 5,6
40025 Tag number - char 7,8
40026 Tag number - char 9,10
40027 Decimal point – flow/totalizer 16 bits int 1
40032 Totalizer alternate, low word 32 bit float 2
40033 Totalizer alternate, high word
PN: 47-0493-C
* Format = mmdd
yyyy
(decimal)