Figure 5.8-2: Wiring Recommendation When Using The 907-485E In 485 Mode (Ch1 Shown); Table 5.8-1: 485/422/Ttl Data Connector Pin Outs; Table 5.8-2: Input / Output Ratings - Moog 903 User Manual

903-0623-00 Rev. A

Figure 5.8-2: Wiring recommendation when using the 907-485E in 485 mode (CH1 shown)

Notes:
1. Twisted pair cable with 120 ohm nominal characteristic impedance (Z
or less) should be used.
2. A terminating resistor must be placed at the end of the cable (external RS-485 device side as shown
in Figure 5.8-2). The terminating resistor (R
impedance of the twisted pair. For example: R
used has nominal Z
the data.
3. The maximum length of the cable used to connect the 907-485E card and an external RS-485 device
should not exceed 10 m (assuming conditions in the notes above are met). For any length larger than
10 m, terminating resistor should be used at both ends of the cable.
4. When the 907-485E card is configured for 422 mode, a 120 ohm termination exist across pins
422RX+ and 422RX-.
The LEDs on the 907-485 board are not visible at the front panel once the card is mounted on the
907-EURO.
Table 5.8-1 shows the data connector pin outs of the 907-485E card. Transmit (TX+/-) and receive
(RX+/-) lines are relative to the board.
CH PIN
1
2
A
3
4
5
6
B
7
8
Table 5.8-2 shows the input / output ratings of the 907-485E card.
*Any values in excess of absolute maximum ratings may damage the electronics. Product specifications
may not be met if the device is outside the operation range.
Focal Technologies Corp.
= 120 ohm. Large impedance mismatches create reflections that cause errors in
0

Table 5.8-1: 485/422/TTL Data Connector Pin Outs

CONN J1
422RX+/TTL IN
422RX-
485+/422TX+/TTL OUT
485-/422TX-/TTL GND
422RX+
422RX-
485+/422TX+
485-/422TX-

Table 5.8-2: Input / Output Ratings

ABSOLUTE*
SIGNAL
MAX. INPUT
RS485/422
+/- 13V
Model 903 User's Guide, FMB-X-2.5 Version
) should be the same value of the characteristic
T
= 120 ohm should be used when the twisted pair
T
CONN J2 CONN J3
422RX+ 422RX+
422RX- 422RX-
485+/422TX+ 485+/422TX+ 485+/422TX+
485-/422TX- 485-/422TX-
422RX+ 422RX+
422RX- 422RX-
485+/422TX+ 485+/422TX+ 485+/422TX+
485-/422TX- 485-/422TX-
ABSOLUTE*
MAX. OUTPUT
+/- 13V
) and low capacitance (60 pF/m
0
CONN J4
422RX+
422RX-
485-/422TX-
422RX+
422RX-
485-/422TX-
PROTECTION
15KV ESD
ISOLATED
Page 5-41