Section 3--Internal Link And Dip Switch Setup; Removal Of Top Cover; Watchdog Enabled/Disabled Link (Lk1); Port 1 - Port 4 Rs-485 Line Biasing/Termination Link (Lk2) - DAQ IoG User Manual

Callisto IoG
D A Q E L E C T R O N I C S

Section 3--Internal Link and DIP Switch Setup

3.1 Removal of top cover

In order to access the links LK1, LK2, LK3, LK4, and the DIP switch SW2; it is first
necessary to remove the top cover from the IoG case. Merely turn the thumbscrew at the
back of the case counter-clockwise until it disengages from the case, and then slide the
top cover rearwards until it is free from the case. The thumbscrew is held captive in the
top cover, so there is no danger of losing it.

3.2 Watchdog Enabled/Disabled Link (LK1)

This link is provided with a shorting jumper installed as shipped from the factory. The
shorting jumper should not be removed. This link is provided for purposes of program
debugging, and is intended for use by qualified personnel only.
3.3 Port 1 – Port 4 RS-485 Line Biasing/Termination Link (LK2)
The LK2 link is utilized when one or more communication ports have been set up for RS-
485. This link group provides 5 VDC and 0 Volts line biasing for better electrical noise
immunity, and also properly terminates the communication line by placing a 120 ohm
resistance in parallel with the high and low signal lines.
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