When a Realflo flow computer is loaded and running in a SCADAPack controller, the flow computer reserves a range of Modbus registers for flow computer use only. Modbus registers that are not being used by the flow computer may be used by the logic program.
The following tables illustrate which Modbus registers are reserved by the flow computer and which Modbus registers are available for use by the controller logic.
The same is true for the older ‘legacy’ SCADAPacks, the newer SCADAPack32 and SCADAPack 300 series controllers as well as for the newest SCADAPack x70 controllers.
Realflo Reserved Modbus Registers
The Realflo Flow Computer reserves the following hard-coded set of Modbus Registers.
Register Type | 5-Digit Addressing Range | 6-Digit Addressing Range |
Discrete Coils | 3800 – 4096 | 3800 – 4096 |
Discrete Inputs | N/A | N/A |
Input Registers | 34000 – 39999 | 304000 – 313999 |
Holding Registers | 42000 – 49999 | 402000 – 411999 |
Realflo Registers Available for Users for standard SCADAPack Controllers
The following Modbus Registers are available for use with ladder logic programming.
Register Type | 5-Digit Addressing Range | 6-Digit Addressing Range |
Discrete Coils | 00001 – 03799 | 00001 – 03799 |
Discrete Inputs | 10001 - 14096 | 10001 - 19999 |
Input Registers | 30001 – 33998 * | 300001 – 303998 * |
Holding Registers | 40001 - 41998 | 400001 – 401998 |
* For SCADAPack 32 and 3xx controllers (i.e. SP32, SP334, SP357, etc) the ‘Input Registers’ range is 30001 – 39999 and 300001 – 303998
For older SCADAPack controllers (i.e. SCADAPack, SCADAPackLP, SCADAPack100, etc) the ‘Input Registers’ range is 30001 – 31024 and 300001 - 301024
Realflo Registers Available for Users for x70 Controllers
The following Modbus Registers are available for use with ladder logic programming.
Register Type | 5-Digit Addressing Range | 6-Digit Addressing Range |
Discrete Coils | 00001 – 03799, 04097 - 09999 | 00001 – 03799, 04097 - 09999 |
Discrete Inputs | 10001 - 14096 | 10001 - 19999 |
Input Registers | 30001 – 33998 | 300001 – 303998 |
Holding Registers | 40001 - 41998 | 400001 – 401998, 412000-465536 |