Intek RheoVac CMS - Manual (Page 31)

September 2013 27 © Intek, Inc. 2013
Revision D
Table 8: Modbus server global settings
Address Description Allowed Values Default Format Read Only?
0001 Restart Modbus Server
Write ‘1’ to restart
0 16-bit unsigned No
0002 CMS Serial Port Set to ‘0’ internally by
CMS System 0 16-bit unsigned Yes
0003 Baud Rate 2400,4800,9600,14400,
19200 bps 9600 16-bit unsigned No
0004 Data Bits 7 or 8 8 16-bit unsigned No
0005 Stop Bits 0 = 1 stop bit
1 = 1.5 stop bits
2 – 2 stop bits 2 16-bit unsigned No
0006 Parity 0 = No Parity
1 = Odd Parity
2 = Even Parity
3 = Mark Parity
4 = Space Parity 0 16-bit unsigned No
0007 Modbus Address 1 – 255 1 16-bit unsigned No
0008 Communication Mode 0 = RTU
1 = ASCII 0 16-bit unsigned No
0009 Conversion Mode 0 = Multiplied Integer
1 = Single Float 1 16-bit unsigned No
0010 Number of Probes 1 – 255 1 16-bit unsigned Yes
4.2.2.2 Modbus data settings (Multiplied Integer Mode)
The values listed in Table 9 are examples of how the Modbus server stores “Multiplied Integer”.
“Multiplied Integer” mode can be enabled by writing a “0” to register 09. The address for the multiplier
is the holding register equivalent of the input register parameter it is multiplying. These register values
determine the power of 10 that is used to multiply each parameter (effectively shifting the decimal point)
before it is transmitted as a 16-bit unsigned integer.
Table 9: Modbus example data holding registers
Address Description Allowed Values Default Read Only?
8001 Multiplier power for TC1-1 0 – 3 16-bit unsigned No
12005 Multiplier power for RheoVac MSP Actual Volume Flow 0 – 3 16-bit unsigned No
12007 Multiplier power for RheoVac MSP Total Mass Flow 0 – 3 16-bit unsigned No
12009 Multiplier power for RheoVac MSP Water Vapor Flow 0 – 3 16-bit unsigned No
4.2.2.3 Modbus data registers (Multiplied Integer Mode)
When in Multiplied Integer Mode, the CMS data values are multiplied by a power of ten
specified in the registers listed in Table 9. The resulting values are then transmitted as 16-bit unsigned
integers. Each value therefore needs only 1 register (2 bytes) of allocated space. In this mode, the data
registers are allocated in pairs, with each data value followed by the multiplication power corresponding
to it. For example, assuming all multiplier registers are set to 3, the RheoVac MSP Pressure is
transmitted as follows:
RheoVac MSP Pressure (probe reading) = 1.257
Input Register 12011 (RheoVac MSP Pressure) = 1257
Holding Register 12011 (Multiplier Value) = 3
All other instruments can be calculated the same way substituting the correct address in place of
12011. The addresses for each instrument can be found in SECTION 8 - CUSTOM INFORMATION.