HMR2300-D00-232 Honeywell, HMR2300-D00-232 Datasheet - Page 9

• Manufacturer Part Number: HMR2300-D00-232
• Manufacturer: Honeywell

Specifications of HMR2300-D00-232

• Lead Free Status / RoHS Status: Not Compliant

HMR2300
PARAMETER SELECTION VERSUS OUTPUT SAMPLE RATE
DEVICE ID
The Device ID command (*ddID=nn) will change the HMR2300 ID number. A Write Enable (*ddWE) command is
required before the device ID can be changed. This is required for RS-485 operation when more than one HMR2300
is on a network. A Device ID = 99 is universal and will simultaneously talk to all units on a network.
BAUD RATE COMMAND
The Baud Rate command (*dd!BR=F or S) will change the HMR2300 baud rate to either fast (19,200 baud) or slow
(9600 baud). A Write Enable (*ddWE) command is required before the baud rate can be changed. The last response
after this command has been accepted will be either BAUD=9600 or BAUD=19,200. This will indicate to the user to
change to the identified new baud rate before communications can resume.
ZERO READING COMMAND
The Zero Reading command (*ddZN) will take a magnetic reading and store it in the HMR2300’s microcontroller.
This value will be subtracted from subsequent readings as an offset. The zero reading will be terminated with another
command input(*ddZF) or a power down condition. This feature is useful for setting a reference attitude or nulling the
earth’s field before anomaly detection.
SET/RESET AND AVERAGE COMMANDS
The set-reset function generates a current/magnetic field pulse to each sensor to realign the permalloy thin film
magnetization. This yields the maximum output sensitivity for magnetic sensing. This pulse is generated inside the
HMR2300 and consumes less than 1mA typically. The Set/Reset Mode command (*ddTN or *ddT) activates an
internal switching circuit that flips the current in a “Set” and “Reset” condition. This cancels out any temperature drift
effects and ensures the sensors are operating in their most sensitive region.
Fluctuations in the magnetic readings can be reduced by using the Average Readings commands (*ddVN or *ddV).
These commands provide a low pass filter effect on the output readings that reduces noise due to Set/Reset
switching and other environmental magnetic effects. The two figures below show the average readings effect for step
and impulse responses.
Switching the set-reset state is not required to sense magnetic fields. A single Set (or Reset) pulse will maximize the
output sensitivity and it will stay that way for months or years. To turn off the internal switching, enter the command
*ddTF or *ddT. In this state the sensors are either in a Set or Reset mode. If the HMR2300 is exposed to a large
magnetic field (>10 gauss), then another set pulse is required to maximize output sensitivity.
In the Set mode, the direction of the sensitive axis’ are shown on the enclosure label and the board dimensions
figure. In the Reset mode, the sensitive field directions are opposite to those shown. By typing *dd], the user can
manually activate a Set or Reset pulse. The S/R pulse commands can be used the continuous read mode to flip
Solid State Electronics Center • www.magneticsensors.com • [phone] • Page 9
Sample
(sps)
Rate
100
123
154
10
20
25
30
40
50
60
9600
yes
yes
yes
yes
no
no
no
no
no
no
ASCII
19,200
yes
yes
yes
yes
yes
yes
no
no
no
no
9600
yes
yes
yes
yes
yes
yes
yes
yes
no
no
Binary
19,200
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
(Hz)
104
131
f
17
17
21
26
34
42
51
85
3dB
100/120
125/150
150/180
250/300
308/369
385/462
Notch
50/60
50/60
63/75
75/90
(Hz)
SENSOR PRODUCTS
Command Input
Rate – min.
(msec)
3.5
20
20
16
14
10
8
7
4
3