User manual
D-2
Appendix D MC-III™ EXP Flow Analyzer
The Floating Point-32 bit (FP32) data type follows the IEEE-754 format and consists of 32 bits contained in a
single register.
The standard word ordering for multiple register data types, such as oating-point numbers or long integers, is
for the most signicant word to appear rst in the message. For master devices requiring the least signicant
word to appear last, a subset of registers is provided on page D-11.
The Unsigned Word (U16) type is used for 16-bit integers and ts into one register.
The Packed ASCII (PA) type contains two bytes that are two unsigned characters. Generally, multiple Packed
ASCII types are arranged consecutively for implementing strings. For example, the device’s well name is a
string of 10 unsigned characters that is implemented as 5 Packed ASCII registers. Here is an example of a
well name that contains the string, “Test Well 413.”
Register Hexadecimal # ASCII Characters
210 54 65 Te
211 73 74 St
212 20 57 <SPACE>W
213 65 6C el
214 6C 20 l<SPACE>
215 34 31 41
216 33 FF 3<UNUSED>
Unused characters at the end of each string will report 0xFF hexadecimal.
Registers
Each register has an Access type: read-only or read-write, as described below.
Access Type Description
Read Only (RO) Register can only be read.
Read/Write (R/W) Register can be read and written.
The registers are grouped into Modbus
®
map blocks based on function. The MC-III contains the following
map functions.
Function Starting Register
System Conguration 1000
Real Time 1200
Input Conguration 2000
Output Conguration 4000
Holding Register (16-bit) 8000 and 17001
Holding Register (32-bit) 7000
Control Registers 70
Wellsite Parameters 200