Magnetek MHR, Руководство пользователя

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MHR Radio Controller Instruction Manual
June 2017
Page 17 of 58
USB (CON1 A2, A3)
It is recommended that the two wires, USB
+
(pin A2) and USB
-
(pin A3), be a twisted pair with 15
twists/meter. Use Vref Com (pin C2) for the ground connection. If you use a chassis or some
other connection for the ground connection of the USB, you could create a damaging ground loop
to your computer system. When plugging in an MHR receiver to a computer system, it is strongly
recommended that a USB isolation hub, like Magnetek PN 195-50645, is used between the MHR
and the computer system.
Vref (CON1 C3)
Vref is a 5V, 100mA max supply provided for the user to power sensors or peripheral interface
devices used with the MHR. To ensure a clean power source, do not use the chassis as the
negative terminal; use pin C2 Vref Com instead.
Analog/Digital Inputs (CON1 E1, E2, E3, F1, F2, F3)
These six pins can be configured as either analog or digital inputs.
Analog voltage range is from 0 to 12V. The analog input utilizes a 10bit analog to digital
converter. The digital voltage range is as follows: inputs less that 2V are a digital 0; inputs
greater than 3V are a digital 1; the output remains unchanged for inputs between 2 and 3V. When
configured for 0 to 12 V inputs, the input source used on these pins must be able to drive 40K
Ohm input impedance.
Assemblies with part numbers in the 178-01790-xxxx range have two 4-20mA analog input pins:
F2 and F3 on CON1. These can only be utilized as analog inputs and cannot be used as digital
inputs. If support for digital inputs is required, then the analog pins that support 0 to 12V should
be used. When configured for 4-20mA inputs, the input source used on these pins must be able
to drive 157 Ohm input impedance.
CAN1 (CON1 A1, B3) CAN2 (CON1 B1, B2)
There are two independent CAN-bus ports on the MHR. Each has a software settable termination
resistor internal to the MHR. The termination resistor should only be enabled if the MHR is the
last device on that end of the CAN-bus and there is no external terminating resistor present.
Current Compensated Outputs, PWM Output, and Digital IO (CON2 A1-H3)
Connector 2 pins A1-H3 can be configured in many different ways. However, they can only be
used to drive the high side of any load.
For any Current Compensated output, the high side of the load should be connected to the IO pin
and the low side of the load should be connected to the return pin (see Figure 08).
For PWM and digital outputs, the high side of the load is connected to the IO pin and the low side
can be tied to a chassis ground (see Figure 09) or to the return pin on the MHR to alleviate the
need for an external diode when driving inductive loads (see Figure 08).
Keep in mind that the total current for any single pin is limited to 3 Amps. Therefore, if
both IO1 and IO2 were configured as digital outputs and had their low sides returned to
the MHR return1 pin, the sum of the current on IO1 and IO2 must not exceed 3 Amps. If 3A
is needed on both IO1 and IO2, the low side of the load must be connected to a chassis
ground, where an external diode is needed.
See the Con2 table (Table 3) for IO/Return Line pairs.