Front panel control, 254 filter steps, 9 gain steps, interface, signal level indication - now with more offset.
- Filter cut-offs from 1 Hz to 127 kHz
- 254:1 adjustment of cut-off frequency
- Gain in 1,2,5,10,20 steps to x 500 (+54dB)
- Signal level indication
- Filter bypass
- Range of Standard Filter Responses
- 2 Rugged Racks, AC or Optional DC power
- Single ended / Differential / IEPE inputs
- Interface option
- Input overload indication
- BNC inputs & outputs
- Usually ex-stock
1 Channel Mini Rack
16 Channels in a 19" Rack
The Kemo CardMaster 21.255G is a filter card designed for applications requiring occasional manual adjustment of cut-off frequency and gain. The CardMaster 255G can be fully controlled via the optional interface, using simple text based commands sent over Ethernet type hardware. Cut-off for each channel is set using two front panel hexadecimal rotary switches, and gain by two front panel switches. CardMaster 21.255G is a member of the Series 21 family of signal conditioning components and can be used in mixed systems comprising different cards from the Series 21 filters. Gain of 1, 2, 5, 10, 20, 50, 100, 200 and 500 is set by front panel switches. Input configuration is set by on board jumpers.
Up to 18 CardMaster 21.255G s can be fitted to the Kemo 21.18 rack, or 1 in the compact portable DC powered minirack.
The CardMaster 21.255G is based on the Kemo 1600 Series filter module, to provide a filtering solution for applications where filter cut-off frequencies need to changed.
|Channels||1 channel per card, 1 slot in Kemo rack|
|Control||Filter cut-off and gain set by front panel switches. Other parameters by on board jumpers or selectable components.
Optional External control, 10BaseT text based FICL II interface. (19" rack only)
|Frequency||254 cut-off steps, and filter bypass|
|Gain||1, 2, 5, 10, 20, 50, 100, 200, 500, (+54dB) with optional factory fitted output attenuation|
|Filters||1600 series filter modules|
|Filter Responses||Defined by filter modules|
|Input Coupling||AC / DC, Single ended / differential set by internal jumpers|
|Input Overload||Absolute Input overload (single ended or differential)|
|IEPE||4mA 24V current source ( selectable 1-10mA )|
|Signal Level||+/- 10 V pk-pk. (Usually with 'headroom')|
|Signal Offsets||+/- 50% on output, +/- 50% on output single ended only. Factory fitted option.|
|Signal Level Indication||3 colour, 4 signal level, off / green / yellow / red|
|Size||1 Series 21 slot (100x220mm Eurocard)|
|Racks, Size and Weight||21.18 Rack(19") - up to 18 channels, 420 x 155 x 350mm (16.6 x 6.1 x 13.8"), 10 kg, (22 lb) maximum.
21.1 Minirack - 1 channel, 44 x 116 x 270 mm (1.7 x 4.6 x 10.7") 1 kg ( 2.2 lb) maximum.
|Power||21.18 rack 90 -120/180-240 Vac 50/60Hz - Optional DC power
21.1 minirack 9 - 30V DC power
|Frequency Range / Hz||Steps||Frequency Range / Hz||Steps|
|0.2 - 50.8||254 x 0.2 Hz||20 - 5 080||254 x 20 Hz|
|1 - 254||254 x 1 Hz||50 - 12 700||254 x 50 Hz|
|2 - 508||254 x 2 Hz||100 - 25 400||254 x 100 Hz|
|5 - 1 270||254 x 5 Hz||200 - 50 800||254 x 200 Hz|
|10 - 2 540||254 x 10 Hz||500 - 127 000||254 x 500 Hz|
|Filter frequency value set by front panel BCD switches
| '1's switch
Signal level indicator
Single ended / differential
These are:- Butterworth 4 pole (05), and 8 pole (03), Bessel 4 pole (09) and 8 pole (07),
Sharp anti-aliasing type, flat to filter cut-off, (13)
General purpose, flat to cut-off, linear phase(41)
General purpose 6 pole (37), compatible with earlier versions of the BenchMaster 21M ( or VBF 21M)
The filter response is specified at order, any questions about which one, contact us and we are pleased to advise you.
Inputs and Gain
Block Diagram of CardMaster 255G
Signal Level Indication
CardMaster 21.255G cards have a signal level indication LED fitted between the input gain stages and the filter. Signal level indication:- 0%- off -10% - green - 70% - orange - 95% - red.
Optional Signal Offset
CardMaster 21.255G cards are now fitted with additional offset on the single ended input, and on the output, up to +/- 5V offset can be applied to the signal making them suitable for use with 0-5V or similar unipolar data acquisition systems.
The Kemo 21.18 rack and CardMaster 21.255G cards are designed for fitting special connectors. These can be fitted to the rear panel, or to a spare slot on the front. Typically we have fitted 25 way 'D' type connectors, with all the filtered outputs on one front panel connector. We have also fitted customer specific connectors to the rear panel. Let us know what you would like.
Optional External Control
CardMaster 255G filters are fitted with control logic compatible with the Kemo FICLII interface for external computer control.
Simple text commands are used, the screen image shows typical commands sent via HyperTerminal.
igna,3,1 - sets channel 3, input gain block A to x1.
freq,3,92 - sets channel 3, frequency to value 92 ( base frequency x 92)
igna,2,5 - sets channel 2, input gain block A to x5.
imod,2,se - sets channel 2, input mode to Single Ended.
icpl,2,dc - sets channel 2, input coupling to DC.
rdbk,2 reads back all the current settings for channel 2.
The RDBK (readback) command gives a listing of all the commands.
RDBK,A will readback all the settings for all 64 channels.
Typical response time to send commands to one channel and implement the settings is about 200mS. Typical response time to refresh all 64 channels is about 15 seconds.
The interface will accept text files, so complete set up information for multi-channel filter systems can be sent as one file. the RDBK files can be stored as text files, so test setups can be stored for measurement audit purposes. An infinite number of racks may be linked for channel counts above 8. (18 slots in rack, each BenchMaster 21M takes 2 slots, less one for interface card)
DC power, 9-30V DC input is available as an option for Kemo 21.18 racks, with an AC 'power brick' to power the unit from mains when available.
Please check our page about DC Power.
The LED indicators on the CardMaster 255G can be turned off by on board jumpers.