Biomark RM310 FAQ
v.1.0 3.14
1: What is the suitable range of coil inductance for the RM310?
The RM310’s inductance range is 215 µH to 265 µH.
2: What is the Q value for the RM310 with 6 volt operation? 12 volt operation?
The Q value should be is measured as close to 134.2kHz as possible (min is 100kHz).
3: What is the fixed capacitance value of the RM310?
The fixed tuning capacitance value is 5,000 pF (two 10,000 pF in series), which resonates
with 280 µH at 134.2 kHz. However, due to tuning capacitor tolerances, the antenna
inductance is specified lower than this.
4: What is the fixed inductance value of the RM310?
This actually deals with the dynamic tuning network (DTN), and the correct value is 22
µH, however it is not included in the antenna circuit except during HDX receiving
intervals. Please refer to appendix 1 for further information. A more technical
explanation is available by reviewing US patent 7528725.
5: What is the suggested tuning procedure for an antenna used with the RM310?
Antenna tuning can be done using a conventional analog ammeter with a 1 amp (or
greater) range setting connected in series with the power supply. Please refer to
appendix 2 and 3 for more information on this process.
6: What does the adjustable inductor L2 do and should I actually adjust it?
The adjustable inductor L2 aligns the HDX receiver. The L2 inductor was pre-set at
Biomark and adjustment may result in a decrease in HDX performance.
Biomark RM310 FAQ cont.
7: I am a biologist. I should be able to use the RM310 without basic electronics knowledge
right?
In fact this is not the case. The RM310 is a ‘do it yourself’ product that is intended for
customers who have strong backgrounds in electronics. The RM310 can be finicky and
easy to burn out, damage, or simply fail to operate if the antenna coil is not constructed
correctly. It is highly advised that potential buyers are aware of these risks and accept
the technical challenges an RM310 system can entail.
8: RM310 seems a bit out of my league. What else is available that will work with my homemade antennas?
The product that you are looking for is the IS1001 ACN. It comes in two versions, 12V or
24V. The IS1001 is an auto-tuning, memory enabled, state-of-art RFID reader. More
information on the IS1001 can found at www.biomark.com.
9: The IS1001 system sounds WAY better than the RM310. Should I make the switch to the
IS1001?
Absolutely. You will be surprised by how much stress and time you will save by doing
so. It can also save you money. Did you know that although the RM310 price point is
low, by the time you add the other necessary components to the system it can surpass
the cost of an IS1001? Fact.
Appendix I
Allflex EID ISO Readers with Dynamic Tuning®
Allflex EID ISO Readers, equipped with Dynamic Tuning®, provide improved reading distance and noise
immunity by optimizing the electrical characteristics of the reader antenna while tags are being read.
ISO readers must read two types of tag technologies, HDX and FDX-B, but these tags use different
signals to convey their identification codes to the reader. Conventionally, a reader’s antenna has fixed
characteristics that balance the performance of both types of tags, but that cannot optimize the
performance of either type. Allflex’s Dynamic Tuning® technology overcomes this compromised
performance of fixed characteristic antennas, and improves reading distance while decreasing
susceptibility to electrical noise interference.
Amplitude
To understand how Dynamic Tuning® works, a basic understanding of reader and tag signals is
necessary. As shown in the figure below, the reader transmits a 134.2 KHz signal, represented by the red
vertical line, that both types of tags use for activation power. While this activation signal is being
transmitted, the FDX-B tag transmits its identification code using signals represented by the green vertical
lines. Subsequently, the activation signal is interrupted, and the HDX tag transmits its identification code
using signals represented by the blue vertical lines.
124.2
KHz
134.2
KHz
Frequency
So that a reader’s antenna can transmit the activation signal, and so that it can receive both types of tag
signals, the antenna must have a characteristic similar to the violet curve in the above figure. An antenna
with this shape is sufficiently broad so that it captures both types of tag signals, but it is correspondingly
limited in its height, or amplitude. This means that the antenna is less than optimally efficient for
transmitting the activation signal, for optimizing the received signal strengths of the both types of tags,
and for rejecting electrical noise interference that might be present.
A more efficient antenna, such as the one shown by the solid black curve, can transmit the activation
signal more efficiently due to its greater amplitude characteristic, and thus activate tags at a greater
distance. However, changing the antenna’s amplitude characteristic in this manner correspondingly
decreases its width. As can be seen in the above figure, such an antenna, represented by the solid black
curve, is not sufficiently wide to capture the HDX tag signal that appears at 124.2 KHz. Thus, heretofore,
it has not been possible alter the antenna characteristics in order to improve the performance of one type
of tag without degrading the performance of the other type of tag.
However, if the reader antenna could have the characteristic shown by the solid black curve while
transmitting the activation signal and receiving the FDX-B tag signal, and have the characteristic shown
by the dashed line black curve while the activation signal is interrupted and the HDX tag signal is being
received, improved reader performance can be attained. Allflex EID ISO readers with Dynamic Tuning®
technology alter the antenna characteristics in this manner, and produce increased activation signal level,
improved tag signal reception, and diminished noise susceptibility, together yielding improved reader
performance.
Appendix II
Appendix III
Reader PCB Assembly
Ammeter
with 1 Ampere
fullscale range
Red
Blk
6 Volt
Battery
Panel Reader Antenna
Figure 1(a)
largest values
To Exciter
Amplifier Output
Equivalent Circuit
smallest values
Figure 1(c)
Figure 1(b)
Antenna
Panel Reader Tuning Procedure
The attached drawing should help illustrate the tuning procedure that is described herein. First, obviously is removing the panel reader's compartment cover, which is retained
with 14 hex-head cap head screws. A 3/32" hex key is required to accomplish this. Since tuning is only required when the installation site construction is such that the antenna
has become detuned, it is necessary to leave the antenna mounted in its intended position. The panel reader module, however, must be removed and inverted in order to access
the tuning jumpers.
Step 1 – With the Panel Reader Module connected to the antenna terminals, and with the reader's power leads connected to a 6 volt battery using the red wire connected to
battery + and the black wire connected to battery -, you should observe the reader's red indicator light flashing, indicating that the exciter is active. You may be able to read an
eartag, although the distance may be less than 1 meter (for HDX). When an eartag is successfully read, the green light will flash momentarily.
Step 2 - Connect an ammeter in series with the battery's + lead as shown in the attached Figure 1(a). An ammeter with an analog readout (an indicator needle rather than a
digital display) will work best. You can use a digital meter, although it will work best if you place the Panel Reader in a continuous on exciter mode (rather than its normal
pulsed mode). To do this, connect the Panel Reader’s RS232 serial port to a PC or PDA that has a terminal emulator program capability (such as Hyperterminal), and send the
Panel Reader the command K00 (upper case letter K followed by two zeroes). You will notice the red indicator light stops flashing and is on steady. Placing the Panel Reader
in this mode stabilizes the input current, and makes the reading easier to read. (Note: Cycling power to the panel reader after completing the tuning process automatically
restores the pulsed exciter mode.)
Step 3 – If the K00 command is not used, you should observe the ammeter needle wavering a bit around a reading of approximately 500 milliamperes (mA) (note: the wavering
indication is caused by the pulsed exciter signal). If the ammeter indicates a current less than 400mA, the antenna is out of tune, and the capacitor tuning jumpers will need to
be adjusted. If you have invoked the K00 command, these current readings will be approximately 25% higher. You may need additional tuning jumpers in order to attain best
tuning, or you may find that some jumpers are no longer required. If the ammeter is reading at least 400 mA, but yet HDX eartag read distance is less than 90cm, then there
might be an interfering noise source somewhere nearby that will need to be removed. (Note: PC displays, especially flatscreens, and other RFID reading equipment will cause
the greatest interference and reduction in read range. AC equipment, such as lights, will not be especially harmful, although if such lights use dimmer controls, there may be
interference.)
Step 4 - If the ammeter is reading less than 400mA, capacitor jumpers must be adjusted to tune the antenna circuit and thereby increase the exciter power. Start with the
jumpers identified as "smallest values" and work toward the "largest values" (see Figure 1(c)). As shown in the equivalent circuit of the capacitor tuning network (Figure 1(b)),
adding jumpers has the effect of paralleling additional capacitors in order to increase total capacitance and thereby reach the optimum tuning point. The optimum tuning point
is attained when the maximum input current reading is achieved. Continue adding or removing capacitance as long as the input current continues to increase (until the input
current decreases with the next incremental capacitance). As much as possible, capacitors should remain balanced on the two sides -- that is, jumpers should appear in the same
positions on both sides of the PCB. A difference of one jumper on a small value capacitor will not cause any problems. The capacitors have progressively larger values -assuming the smallest is 100pf (picofarads), the next one is 220pf, the next 470pf, the next 1000pf, and the last 1500pf. This approximate "binary" progression provides the
greatest tuning range with the fewest capacitors, but does require combining jumpers in patterns that add up. For example, a jumper on the first and third locations results in
570pf.
Step 5 - Attaining the optimum tuning point is a matter of experimentation. First, be sure to make a note of the factory set positions of the jumpers. If you are not able to make
any improvements with this procedure, performance is still likely to be best with the factory setting, so return the jumpers to their original positions if no improvement is
possible. Start by removing some of the smaller value jumpers. If removing jumpers makes the meter reading drop, then more jumpers need to be added. If removing jumpers
makes the meter reading increase, the fewer jumpers are required, or jumpers may need to be repositioned for best performance. Jumpers should be added in incremental steps,
as defined in the attached table, starting with the smallest value and working toward larger values, while observing the ammeter reading. Continue to add or remove jumpers
for as long as the ammeter reading continues to indicate increasing current. At some point, more capacitance will begin to decrease current, indicating the optimum tuning
point has been passed. If you observe the addition or removal of jumpers are not having any effect on the meter reading, you may want to make read range tests with a
transponder in order to determine what jumper setting is best.
The following table represents the jumper positions and the incremental sequence in which jumpers should be added for tuning:
Largest Capacitor
Value – 1500 pf
1000 pf
470 pf
220 pf
Smallest Capacitor
Value - 100 pf
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Total Tuning
Capacitance
0
100
220
320
470
570
690
790
1000
1100
1220
1320
1470
1570
1690
1790
1500
1600
1720
1820
1970
2070
2190
2290
2500
2600
2720
2820
2970
3070
3190
3290