Rice Lake Condec UMC600IS - Manual (Page 21)

18 UMC 600IS Installation Manual
3.3.2 Option 2 – Analog Output
Option 2 enables the analog output option. The following features of analog output are;
• Converts serial data into analog: 0–10VDC or 4–20 mA
• Ordered as a kit, it must be operated remotely from the digital weight indicator
• Self-powered, 115 VAC provides isolated output
• Automatic data checking/verification
• Analog output tracks gross, net, or displayed weight
• Full digital calibration (indicator front panel)
• Serial data “pass-through”
Serial data from the indicator is modified to include scaled information special for the analog output module. The
standard communications are also included to allow the module to pass-through printer or scoreboard
information.
NOTE: The serial pass-through does not have duplex capability.
The analog output is fully isolated with its own power supply and current loop communications. The analog
module can be located remotely up to 1000 feet from the indicator but must be located in the safe area. After
wiring and setting the module’s baud rate, the remaining setup and calibration is done at the indicator.
Specifications
Current output is 4–20 mA with a maximum impedance less than or equal to 600 Ω.
Voltage output is 0–10 VDC with a minimum load resistance of 1k Ω.
Test Modes
Switch settings are provided to force the analog output to zero, full scale, or to provide a continuous sawtooth
waveform for system checking.
Error Checking
Serial data is continually checked for parity, valid characters, and presence of communication. Loss of data is
indicated by forcing the analog output to a minimum value of 0.5 VDC or 3.2 mA (approximate). If the indicator is
in an overload condition, the analog output is forced to 5% over full scale. With the 4–20 mA output, an additional
alarm is provided to detect the lack of current (break) in the loop.
Communication Verification
An LED (DS1) is provided on the analog module:
• ON = Communications OK
• Pulse = Communications errors
• OFF = No power
Calibration
Using the host, settings are provided for zero, span, and trim adjustments. The settings are all digital therefore no
potentiometers are required. During the trim adjustments for zero/span, the analog output is forced to the
zero/span previously selected in option mode parameters 2.5 and 2.6. While reading the analog output, the trim is
increased or decreased from 0 to ± 175 until the reading agrees with the values entered in 2.5 and 2.6.