Red Lion GEMINI 2 - Manual (Page 27)

CURRENT LOOP INSTALLATION
WIRING CONNECTIONS
When wiring the 20 mA current loop, remove the 7-position terminal block
(TBD), located on the right side of the top board. Refer to the numbers listed with
the terminal descriptions below or on the top label, and install each wire in its
proper location on the terminal block. When all connections are made, replace
the terminal block into its proper location.
It is recommended that shielded (screened) cable be used for serial
communications. This unit meets the EMC specifications using Alpha #2404
cable or equivalent. There are higher grades of shielded cable, such as, four
conductor twisted pair, that offer an even higher degree of noise immunity.
TERMINAL DESCRIPTIONS FOR TERMINAL BLOCK TBD
1. -20 mA SRC (COMMON) - Common for 20 mA SRC & Print Request
terminal.
2. PRINT REQUEST - The Print Request Terminal is connected to common to
request the Gemini 2000 to transmit according to the Print Options mode that
has been selected. (Minimum Activation time = 25 msec.)
3. +20 mA SRC - The 20 mA SRC terminal provides the source current for one of
the loops.
4. SO- (Serial Out-)
5. SO+ (Serial Out+)
The Gemini 2000 transmits the requested data on these terminals (SO- &
SO+). They are connected in series to the receive input of the device to be
connected.
6. SI- (Serial In-)
7. SI+ (Serial In+)
The Gemini 2000 receives commands on these terminals (SI- & SI+). They are
connected in series with the transmit or output terminals of the device to be
connected.
Note: The serial input terminals must be held in the mark condition
(current on) in order for the Gemini 2000 to respond to a Print Request
terminal activation.
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