Macurco DVP-1200, Manual

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Macurco TM DVP-1200 Manual
REV – 1.3.1 [34-8708-4770-7 ] 16 | P a g e
For any other baud rates calculate when (at what length) termination resistors are required. This is calculated by dividing the
length L by the ratio between the new baud rate and 19200 or (x/19200) where x is the new baud rate.
𝐿𝐿
( 𝑥𝑥 19200 𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏 ⁄ )
For example, if new baud rate is 9600
1000 𝑓𝑓𝑓𝑓
(9600 𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏 19200 𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏
⁄
) =
1000 𝑓𝑓𝑓𝑓
0.5 = 2000
𝑓𝑓𝑓𝑓
Use termination resistors when cables are longer than 2000 ft.
For example, if new baud rate is 38400
1000 𝑓𝑓𝑓𝑓
(38400 𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏 19200 𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏 ⁄ ) =
1000 𝑓𝑓𝑓𝑓
2
= 500 𝑓𝑓𝑓𝑓
Use termination resistors when cables are longer than 500 ft.
NOTE: Other manufacturers may have different recommendations on wire length and EOL resistor usage.
Figure 3-9 –
At 19200 baud rate (default), 1000 ft or less, and using RS-485 or Cat-5 type cable