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IronHorse GSDA-CM-8 User Manual – 1st Ed. Rev. A – 10/15/19
Using the Analog Input
The GSDA-CM-8 has a built-in analog to digital converter. This input may be used in lieu of a digital
pick-up signal or to control Target speed, current program, or frequency generator output frequency.
To use this input with a potentiometer source, connect a pot wiper to Pin 7 of the serial interface port,
pot high to the +5V terminal, pot low to the Common terminal. The pot should have a resistance from
500 to 5k ohms. Parameters 5040-5043 set destination source type and range for the analog input.
Adjusting the values in parameters 5042 and 5043 allows the pot source range to be scaled between
the “Analog Input Minimum” and “Analog Input Maximum” values. A 0 to +5V signal may be used
instead of a potentiometer, connect signal to pin 7 of RJ45 and common to pin 6 of the RJ45 (P2-6).
Parameter 5041 should be set for source type.
RJ45 Pin
Signal Description
1
RS232 Rx (Receive data)
2
No Connect
3
TxD+, RxD+ (+transmit/receive data line)
4
TxD-, RxD- (-transmit/receive data line)
5
Frequency generator out (Do not use for
RS232 communications)
6
Circuit Common, Signal Ground
7
Analog Input (0 to 5 VDC)
8
RS232 Tx (Transmit data)
Overview
The GSDA-CM-8 analog input uses 2 pins on the RJ45 “modular” connector, and can be used with
a variety of signals. The signal from the analog input source can be used to provide control or
“feedback” information to the GSD8 drive. This application note will cover five major topics:
•
Types of Signal Sources
•
Analog Source Signal Processing
•
Analog Source Signal Assignment
•
Analog Source Signal Configuration
•
Analog Source Signal Processing
Types of Signal Sources
The analog input of the GSDA-CM-8 has been designed to use three types of analog signal sources:
•
Potentiometer (500W to 5kW only)
•
0 to +5VDC Voltage Source (source impedance < 5kW)
•
4 to 20mA Current Source (impedance = 250Ω 0.1%, customer supplied)
NOTE: Signals should be 0 to +5 VDC ONLY!
Analog Source Signal Processing
Correctly selecting the signal source type is important to insure optimum performance of the drive
when using the signal. Processing of the signal source type by the GSDA-CM-8 is explained in the
sections below.
Potentiometer Input:
Noise can be a problem when using a potentiometer input signal. In order to prevent the GSD8 drive
from responding to such noise, the selection of the “Potentiometer” type of input sets a deadband
that filters the potentiometer input. From zero speed, the deadband filters changes of less than
10%; requiring a change of 10% or more in the potentiometer input signal before the GSD8 drive will
respond. With the drive running at speeds greater than zero, the deadband changes to filter input
signal changes of less than 5%.
