Fan Tray Specification
The fan tray is an additional module to the main 3U DI/OT crate for systems that require better heat dissipation (especially in radiation-free areas). The fan tray contains 3x 12VDC fans and a Monimod board to control these fans and communicate with a DI/OT crate. The fan tray shall meet the following requirements:
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1U (1 rack unit) height enclosure compatible with 19" racks - preferably assembled using off-the-shelf 19" crate components or reusing a full off-the-shelf 1U enclosure;
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Equipped with 4 rack mounting holes;
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15-pin D-SUB connector of the Monimod exposed in the front panel to get power and control signals from a DI/OT crate (Monimod step model is provided to verify mechanical design of the fan tray);
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Equipped with three (120mm, 12VDC, tachometer, no PWM) fans - San Ace 9G1212G101 (or compatible) - each connected to a 3-pin MoniMod fan connector;
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Bottom to top air flow;
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Equipped with a dust filter;
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The placement of fans and Monimod shall be compliant with the figure below:
Files
- MoniMod-FanTray step model: monimod-fantray.step
Monimod-FanTray PMBus communication
DI/OT Fantray integrates inside a monitoring/control module called Monimod-FanTray. Monimod-FanTray is an execution of a generic MoniMod monitoring module (see also Monimod project page) and communicates with DI/OT System Board using a set of PMBus commands.
This section contains only fantray-specific Monimod documentation, while a full set of supported PMBus commands can be found at dedicated detailed Monimod PMBus documentation page.
Reported monitoring values
Command code | PMBus page | PMBus command | Sch label | Description |
---|---|---|---|---|
8B | 0 | READ_VOUT | V_adc1 | 12V rail voltage |
8C | 0 | READ_IOUT | I_fan1 | FAN1 Current |
8B | 1 | READ_VOUT | V_adc2 | 5V rail voltage |
8C | 1 | READ_IOUT | I_fan2 | FAN2 Current |
8C | 2 | READ_IOUT | I_fan3 | FAN3 Current |
8D | - | READ_TEMPERATURE | T_adc1 | FanTray temperature |
90 | - | READ_FAN_SPEED | Fan_tacho1 | FAN1 RPM (System Slot + Peripheral Slots 1-4) |
91 | - | READ_FAN_SPEED | Fan_tacho2 | FAN2 RPM (Peripheral Slots 5-8) |
92 | - | READ_FAN_SPEED | Fan_tacho3 | FAN3 RPM (Power Supplies) |
3A | - | FAN_CONFIG | - | Fans 1 & 2 configuration |
3D | - | FAN_CONFIG | - | Fan 3 configuration |