Emerson Process Management 1500 manual Changing the floating-point byte order

Optional Transmitter Configuration

6.12.4Changing the floating-point byte order

Four bytes are used to transmit floating-point values. For contents of bytes, see Table 6-7.

Table 6-7Byte contents in Modbus commands and responses

Byte	Bits	Definitions
1	S E E E E E E E	S = Sign
		E = Exponent
2	E M M M M M M M	E = Exponent
		M = Mantissa
3	M M M M M M M M	M = Mantissa
4	M M M M M M M M	M = Mantissa

The default byte order for the transmitter is 3–4–1–2. You may need to reset byte order to match the byte order used by a remote host or PLC. Byte order codes are listed in Table 6-8.

Table 6-8Byte order codes and byte orders

Byte order code	Byte order
0	1–2–3–4
1	3–4–1–2
2	2–1–4–3
3	4–3–2–1

Using the Transmitter

Optional Configuration

6.12.5Changing the additional communications response delay

Some hosts or PLCs operate at slower speeds than the transmitter. In order to synchronize communication with these devices, you can configure an additional time delay to be added to each response the transmitter sends to the remote host.

The basic unit of delay is in terms of 2/3 of one character time as calculated for the current serial port baud rate setting and character transmission parameters. This basic delay unit is multiplied by the configured value to arrive at the total additional time delay. You can specify a value in the range 1 to 255.

6.13Configuring variable mapping

The Variable Mapping panel in the Configuration window provides another way to assign the primary variable (PV). The PV parameter shown on this panel is the same as the Primary Variable parameter in the Analog Output panel (see Section 4.5): if you change the parameter here, it is automatically changed in the Analog Output panel, and vice versa.

The secondary variable (SV), tertiary variable (TV), and quaternary variable (QV) are not used by the Model 1500 transmitter with the filling and dosing application, and cannot be changed.

Filler Configuration

Using the Filler

Configuration and Use Manual 51