Specifications

Curtis 1310 Manual, Rev. B

1 6 F E B R U A R Y 2 0 0 8 D R A F T

2 — INSTALLATION & WIRING: Wiring

Analog inputs

Three types of analog inputs are used. The ﬁrst two inputs use a 0–5V input.

The next is a 3-wire connection for a potentiometer using both Pot High and

Pot Low and the third is a 2-wire potentiometer or rheostat.

Note that in all cases, the VCL code must be written to provide the nec

essary wiring and potentiometer fault checking. To accomplish this, the 1310

provides the measured voltage readings of Pot High and Pot Low connections.

Monitoring these values can indicate if there is a short to B+ or B-. Using the

Pot High and Pot Low connections for the potentiometer or rheostat will also

provide a small lower and (when using Pot High) upper bound to the analog

input. Knowing this, proper range checking in VCL can be performed for ad-

ditional fault diagnostics.

Encoder and pulse inputs

The 1310 has two quadrature encoder inputs. Using A and B channels with a

quadrature encoder allows velocity, position (count), and direction detection.

Tying the A and B channels together, as shown on Encoder 2, allows the input

to measure a single pulse train. In this conﬁguration, the 1310 will either count

(ENC_Count mode) or measure speed magnitude (Enc_Velocity mode); the

ENC2_DIR variable is not valid in this conﬁguration.

Power for the encoder can be derived from the +5V output and Ground

pins found on J4. The +5V output has an output current measurement. VCL

can use this value to determine if the encoder and/or any other sensors are con

nected and drawing the proper current. This can be used to provide additional

fault diagnostics.

Note: If the encoder inputs are set up in velocity mode, the direction

ﬂag will not be accurate below a low speed threshold. The direction bit may

stay in the last direction and may not return to 0 when the speed is at zero.

The VCL code must be written to read the velocity variable and doublecheck

the direction bit in this case; see page 36.

Analog outputs

The two analog outputs can be used to interface to various analog devices.

Here, Analog Output 1 is used to control the throttle input of a Curtis 1204

motor controller. Note that most throttle inputs are 0–5 V while the 1310 can

provide up to 10 volts.

Analog Output 2 is being used to drive a gage, such as a Curtis enGage 2

or simple voltmeter. VCL code can use this output to display a wide range of

data—for example, the state of the battery charge, position of the potentiometer

wipers, or speed of the encoder.

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