User guide

Programming Manual
Page 47 March 2014
Modbus Coil Description Modbus Coil Notes
Reset Running Totalizer 1
Forcing this coil ON will reset the running totalizer. After reset, the
coil automatically returns to the OFF state.
Reset Grand Totalizer 2
Forcing this coil ON will reset both the running totalizer and the
grand totalizer. After reset, the coil automatically returns to the OFF
state.
3…8 Spares
Alarm Set point 1 9 0 = Set point OFF, 1 = Set point ON
Alarm Set point 2 10 0 = Set point OFF, 1 = Set point ON
11…16 Spares
Table 11: Modbus coil map
Opcode 01 – Read Coil Status
This opcode returns the state of the alarm coils. The following Coils are defined:
Coil # Description
9 Alarm Set point 1
10 Alarm Set point 2
11 and up Spare
Table 12: Read coil status
Command: <addr><01><00><08><00><02><crc-16>
Reply: <addr><01><01><0x><crc-16>
Opcode 03 – Read Holding Registers
This opcode returns the input holding registers, such as flow rate or totalizer.
OTE:N Each value must be requested individually. Return of a block of registers is not implemented at this time.
Example requesting flow rate in floating point format.
Command: <addr><03><00><C9><00><02><crc-16>
Reply: <addr><03><02><data><data><crc-16>
Opcode 05 – Force Single Coil
This opcode sets the state of a single coil (digital output). The following Coil Registers are defined:
Coil # Description
1 Reset Totalizer
2 Grand Totals
3 and up Spares
Table 13: Force single coil
The transition of coil from 0 to 1 will initiate function. This bit is auto reset to 0, so there is no need to set it to 0 after a totalizer
reset command.
Command: <addr><05><00><00><FF><00><crc-16>
Reply: <addr><05><00><00><FF><00><crc-16>