YZ Systems NJEX 8300G, Manual, Page: 114 / 126

YZ Systems, Inc. • 3101 Pollok Drive • Conroe, Texas • USA • 77303 • P: 936.788.5593 • F: 936.788.5720
Page 107 NJEX 8300G ver.092001 ATEX Rev.
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Communications Settings
Protocol ............................................................................. Modbus
Data framing ...................................................................... Modbus RTU and ASCII
Slave Address range .......................................................... 0-247, 0 = Modbus disabled
Baud rates ......................................................................... 1200, 2400, 4800, and 9600
Number of data bits ............................................................ 7 or 8
Parity ................................................................................. None, Odd, Even
Stop bits:............................................................................ 1 or 2
Serial communications: ...................................................... Redundant RS-485 2 wire
N300 Modbus Function Support
Function Code Function Description
1 ............................. Read Coil Status................... Reads the ON/OFF status of discrete outputs (coils)
3 ............................. Read Holding Registers ........Reads the binary contents of holding registers
5 ............................. Force Single Coil ..................Forces a single coil to either the ON or OFF state
6 ............................. Preset Single Registers ........Presets a value into a single holding register
16 ........................... Preset Multiple Registers ......Presets values into a sequence of holding registers
Boolean Registers
The Boolean data type could be used for status, and control. The discrete outputs or "coils" as defined by the
Modbus specification are read/write registers. This ON/OFF data type can be manipulated using Modbus functions
1 and 5.
The valid address range for this data type is 00001 to 09999.
Function 1, allows reading a single coil per query
Function 5, allows writing single or multiple coils per query.
Control Functions
The control functions available via Modbus are listed below. The registers are accessed using Modbus functions 1
and 5. The master device can initiate a state change by setting a control coil. The N300 controller will clear non-
toggle type coils to acknowledge the state change has been acted upon. Toggle type coils hold their current state
until changed either locally or remotely. The local/remote load cycle control (00007) determines whether a load
cycle can be initiated via contact closure (local) connected to the load cycle inputs on the controller or
by Modbus
coil 00006 (remote). These coils are only active in an N300 Liquid system. Coil 00011 determines whether a
remote inhibit can be initiated by a contact closure (local) connected to the inhibit inputs on the controller or by
Modbus coil 00010 (remote).
Coil 00009 is used to save all the current parameters to the controller EEPROM.
IMPOR IMPOR
IMPOR IMPOR IMPORTTTTTANT
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ANT ANT ANT:::::
Coil 00009, must be used to save any parameters that were changed via Modbus.
Address Access Description
00001 ........... Read/Write ..............Start/Stop the pump (toggle)
00002 ........... Read/Write ..............System Standby (toggle)
00003 ........... Read/Write ..............Reset Accumulated Stroke Count
00004 ........... Read/Write ..............Reset Accumulated Odorant Injected
00005 ........... Read/Write ..............Fill Verometer (toggle)
00006 ........... Read/Write ..............Start/Stop a Load Cycle (toggle) (Liquid System Only)
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ODB ODB ODB ODB ODBUS US US US US
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