JPH01223522A - Connection decision system - Google Patents

Abstract

PURPOSE:To eliminate a need of connection lines and current detecting circuits to not only reduce the cost but also simplify a circuit by deciding whether an option unit is connected or not according to the output of a comparing means goes to the high level or the low level. CONSTITUTION:Outputs of comparators 15A-15C are inputted to a register 18 and are sent to a microprocessor (MPU) 20 through a bus 19. Consequently, the MPU 20 reads out the resister 18, in which outputs of comparators 15A-15C to discriminate whether fans 11A-11C are connected or not. Meanwhile, pulse signals of rotational frequencies of fans 11A-11C are selected through output lines 13A-13C by a multiplexer 21 and are inputted to a counter 22. The counted value of the counter 22 is stored in a register 23 and is sent to the MPU 20 and is compared with a rated value to discriminate whether fans are normally rotated or not. If they are not normally rotated, an alarm is outputted. Thus, the number of connection lines is not increased, and mounting is easy and the cost is reduced, and a current detecting circuit is not required to simplify the circuit constitution.

Description

[Detailed Description of the Invention] [Summary In a co-computer system, a connection determination method for determining whether an option unit is connected or not is provided.
In addition, we aim to provide a connection determination method that allows easy determination at low cost without complicating the circuit configuration. At the same time, a pull-up resistor is provided on the power supply line connected to one terminal of the comparing means, and a reference voltage is input to the other terminal of the comparing means, so that the output of the comparing means is determined based on the output of the comparing means. The system is configured to determine whether or not the option unit is connected.

[Industrial Field of Application] The present invention relates to a connection determination method for determining whether an option unit is connected in a computer system.

Computer systems use fans for cooling, and the number of fans varies even in the same computer system depending on the presence or absence of options.

For example, as shown in FIG. 4, when extracting the rotational speed pulse of fan 1 from fan 1 and monitoring the operation of fan 1 with alarm detection circuit 2, the amount of monitoring depends on whether fan 1 is connected or not. It is necessary to distinguish whether the

When fan 1 is connected and rotating normally, a pulse signal proportional to the number of rotations of fan 1 is output, so this pulse signal is counted by a counter for a certain period of time to ensure that fan 1 is rotating normally. Make sure that In this case, when the count value is below a certain value, the CPU assumes that a failure has occurred in the fan 1 and performs an alarm process.

In such a system, when the fan 1 is not connected, no pulse signal is input to the counter, so it is indistinguishable from a state where the fan 1 is stopped.

Therefore, unless it is determined whether fan 1 is connected or not, alarm processing will be performed erroneously when fan 1 is connected. Therefore, it is necessary to determine whether the option is connected.

[Prior Art] Conventional optional connection determination methods include, for example, those shown in FIGS. 5 and 6, respectively.

In FIG. 5, 1 is a plurality of fans, and these fans 1 send rotating pulse signals to the alarm detection circuit 2 via the pulse signal line 3.

The alarm detection circuit 2 counts rotation pulse signals for a certain period of time and determines whether or not the rotation is normal.

Here, in order to determine whether or not the fan 1 is connected, a connection line 4 is additionally connected between the fan 1 and the alarm detection circuit 2, and the alarm detection circuit 2 receives the connection signal from the fan 1. Based on this, it was determined whether there was a connection or not. Therefore, when the fan 1 is connected, the rotation pulse signal of the fan 1 is used to perform alarm processing.

Next, the connection determination method shown in FIG. 6 will be explained.

In FIG. 6, 1 is a fan, 2 is an alarm detection circuit, and a pulse signal is sent from the fan 1 to the alarm detection circuit 2 via a pulse signal line 5.

A power supply detection circuit 7 is provided in the power supply line 6 of the fan 1, and this detects whether or not the fan 1 is connected.

[Problems to be Solved by the Invention] However, in such a conventional connection determination method, in the case shown in FIG. 5, when the number of fans increases,
There are problems in that the number of connection lines for determining connection increases, which not only makes implementation difficult, but also increases cost.

In addition, in the case of Fig. 6, the number of connection lines does not increase, but
There were problems in that a power supply detection circuit had to be provided, making the circuit configuration complicated and increasing costs.

The present invention has been made in view of such conventional problems, and it is possible to determine whether an option is connected without increasing the number of connection lines and without complicating the circuit configuration. The purpose of the present invention is to provide a connection determination method that allows easy determination at low cost.

[Means to solve the problem] FIG. 1 is a diagram explaining the principle of the present invention.

In FIG. 1, 14 is a resistor connected in parallel to the output line 13 of the option unit 11 connected to one terminal of the comparison means 15, and 17 is a power line connected to one terminal of the comparison means 15. The pull-up resistor 15 provided at 16 is a comparing means to which the reference voltage VREF is input to the other terminal and the output from the output line 13 is input to one terminal thereof.

[Function] In the present invention, when the option unit 11 is connected, the voltage input to one input terminal of the comparison means 15 exceeds the reference voltage VREF, so the output of the comparison means 15 becomes low level, , option unit 1
1 is not connected, the voltage input to one input terminal of the comparing means 15 is lower than the reference voltage VREF, so the output of the comparing means 15 becomes high level.

Therefore, based on the output of the comparison means 15, it can be easily determined whether the option unit 11 is connected.

Therefore, there is no need to increase the number of connection lines and no need to provide a current detection circuit as in the conventional case, so costs can be reduced and the circuit configuration can be simplified. Moreover, implementation becomes easy.

Examples] Embodiments of the present invention will be described below based on the drawings.

FIG. 2 is a circuit block diagram for implementing the present invention.

In FIG. 2, reference numeral 11 indicates a plurality of optional units, and specifically, these optional units 11 are composed of a plurality of fans 11A to 11C. Fan 11A~
Output transistors 12A-12C are provided in 11C, and output lines 13A-13C are taken out from the collector sides of output transistors 12A-12C, respectively.

Resistors 14A to 14C are provided in parallel to the output lines 13A to 13C, respectively.

15A to 15C are comparators as comparison means, and the output lines 13A and 13B are connected to the negative input terminals of the comparators 15A and 1.5B, respectively, and rotation pulse signals are inputted thereto. In this example, the output line 13G of the fan 11C is not connected to the negative input terminal of the comparator 15C.

In addition, the positive input terminals of comparators 15A to 15G are lQ.
The voltage VREF is inputted respectively. Also, comparator 15A
~15C power supply V input to each negative input terminal
Pull-up resistors 17A to 17G are provided in series to the cc power lines 16A to 16C, respectively.

Therefore, since the two fans 11A and IIB are connected, the outputs of the comparators 15A and 15B are at a high level.

On the other hand, since one fan 11C is not connected, the output of the comparator 15C is at a low level.

In this way, it can be determined whether the fans 11A to 11C are connected based on the outputs of the comparators 15A to 15C.

That is, the outputs of comparators 15A to 15G are
8 and is sent from the register 18 to the microprocessor (hereinafter referred to as MPU) 20 via the data bus 19. Therefore, the MPU 20 reads the register 18 in which the outputs of the comparators 15A to 15C are stored, and
It is determined whether or not 1A to 11C are connected.

On the other hand, the fans 11A to 11C output pulse signals having a rotational speed proportional to the rotational speed via output lines 13A to 13C,
This pulse signal is selected by a multiplexer 21 and input to a counter 22. The count counted by the counter 22 (the direct count is stored in the register 23 and sent to the MPU 20. The MPU 20 compares the count value from the register 23 with the standard value and determines whether it is rotating normally. If not, output an alarm.

Furthermore, the MPU 20 controls the select signal of the multiplexer 21, and switches the multiplexer 21 depending on which fan 11A to 11C is to be monitored for rotational speed. Therefore, it is possible to control so that the pulse signal of the unconnected fan 11C is not input to the counter 22.

Next, the connection determination method will be explained.

In Fig. 3, when the fan 11C is not connected, the voltage input to the negative input terminal of the comparator 15C is V.
Since the voltage input to the cc and positive input terminals is VREF, Vcc>VREF, and the output of the comparator 15C is
0 is a low level. This low level signal is sent to the MPU 20 via the register 18, and the MPtJ 20 determines that the fan 11C is not connected based on the output Vo of the comparator 15C from the register 18. MPU20
controls the select signal of the multiplexer 21 based on this, and the pulse signal from the fan 11C is sent to the counter 22.
control to prevent input.

On the other hand, since the fans 11A and 11B are connected, the resistor on the negative input terminal of the comparators 15A and 15B and the resistor R2 on the unit side is a pull-up resistor on the power supply line a)
, will be input to the positive input terminal, so the comparator 15A,
The output VO of 15B becomes high level. Note that even when the rotation is stopped, the outputs Vo of the comparators 15A and 15B are at a high level. This high level signal is sent from register 18 to MP
Based on this signal, the MPU 20 determines that the fans 11A and 11B are connected.

Then, MPtJ20 outputs V from comparators 15A and 15B.
The select signal of the multiplexer 21 is controlled based on the rotation speed of the multiplexer 21, and the multiplexer 21 is switched depending on which fan 11A or 11B rotation speed is to be monitored.

Pulse signals from fans 11A and 11B are selected by multiplexer 21 and input to counter 22. The counter 22 counts the input pulse signals for a certain period of time, and stores the counted value in the register 23. The count value stored in the register 23 is sent to the MPU 20, and the MPU 20 compares this count value with a specified value and determines whether the rotation speed is normal or not. If the rotation speed is not normal, it issues an alarm. Output.

As described above, in this embodiment, there is no need for an increase in the number of connection lines as in the conventional case, the implementation is easy, and the cost can be reduced. Further, unlike other conventional examples, there is no need to provide a current detection circuit, so the circuit configuration can be simplified.

[Effects of the Invention] As described above, according to the present invention, the presence or absence of connection of an optional unit can be easily determined by extracting only the rotation pulse signal, so there is no need to increase the number of connection lines. Further, since there is no need to provide a current detection circuit, costs can be reduced, implementation is easy, and the circuit configuration is also simple.

[Brief explanation of the drawing]

Fig. 1 is a diagram explaining the principle of the invention, Fig. 2 is a circuit diagram showing an embodiment of the invention, Fig. 3 is a diagram explaining the operation, Fig. 4 is an explanatory diagram explaining the invention in detail, Fig. 5 is a circuit diagram showing a conventional example, and FIG. 6 is a circuit diagram showing another conventional example. In the figure, 11...Optional unit, 11A-11C...Fan, 12A-12G...Output transistor, 13A-13
C...Output line, 14A~14C...Resistor, 15A~15C...Comparator (comparison means), 16A~1
6C...Power supply line, 17A to 17C...Resistor, 18.23...Register, 19...Data bus, 20...MPtJ, 21...Multiplexer, 22...Counter. Figure 4 is an explanatory diagram explaining the invention in detail. Figure 5 is a circuit diagram showing a conventional example.

Claims (1)

[Claims] A resistor (14) is connected in parallel to the output line (13) of the option unit (11) connected to one terminal of the comparison means (15).
), a pull-up resistor (17) is provided on the power supply line (16) connected to one terminal of the comparison means (15), and a reference voltage (VREF) is provided on the other terminal of the comparison means (15). ) and select the comparison means (15
) A connection determination method characterized in that it is determined whether the option unit (11) is connected based on the output of the optional unit (11).