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Table 12-3. RS-485, INCOM, and IRIG-B Pin Connections
Pin Number
IRIG-B Minus
64
IRIG-B Positive
63
INCOM
62
61
INCOM
60
+5 VDC at 100 milliamperes
59
Direction minus
58
Direction positive
57
RS-485 common/VDC return
56
RS-485 minus (aux. comm. port)
55
RS-485 positive (aux. comm. port)
RS-485 Port
For all communications hardware options with a single RS-485 port, that port is provided at terminals 55(+), 56 (-), and
57 (com). See Table 12-3.
For communications hardware option #8, dual RS485 ports, terminals 55, 56, and 57 are designated RS485 Rear Port
#2, and pins 1(+), 2 (-), and 7(com) of the COM3 DB-9 connector represent RS485 Rear Port #1.
The RS485 port on the DPU1500R has three associated resistors and jumper links that allow insertion or removal of
these resistors, depending on the location of the relay in the network. Jumper link J6 on the communications card is
for the termination resistor. A termination resistor should be inserted at the first and last devices on the network.
Typically J6 would be set for "IN" for the last relay on the RS485 network; and, J6 would be set in the "OUT" position for
all other relays in the loop. The first unit on the network, typically an ABB 245X series convertor, has the terminating
resistor built-in. For communication hardware option "8," dual RS485 ports, J6 is for Port #2 and a similar jumper, J16
is provided for RS485 Port #1.
Jumper links J7 and J8 insert or remove "pull-up" resistors. These resistors establish a known voltage level on the
RS485 bus when no units are transmitting, in order to reduce noise. These jumpers should be set to the "IN" position
on only one relay at either end of the RS485 loop. If an ABB communications converter, catalog series 245X, is used
on the network, it has these resistors built-in, and all relays can have J7 and J8 in the out position. For communications
hardware option "8", dual RS485 ports, J7 and J8 are for Port #2, and J17 and J18 are for Port #1.
The RS485 cable should be shielded 3 conductor twisted cable. The shield should be grounded at one end of the
communications circuit, preferably where the RS485 circuit begins; eg: at the convertor unit. A typical RS485 connection
diagram, drawing 604765, is available on request from the factory.
Recommended cables are Alpha #58902, Belden #9729, #9842, #9829 and Carol #58902.
Communications Settings
Change communications settings via the man-machine interface (MMI) on the front of the DPU1500R or through
WinECP. When you use the MMI, the communications ports are blocked from downloading settings but can still
retrieve data. Similarly, when a communications port is downloading new settings, the MMI and other communications
ports are blocked from changing or downloading settings but not from retrieving data.
Ordering Information/Communications/Panel Mounting/Spare Parts
Pin Number
ABB Distribution Protection Unit 1500R
website:www.abb.com/papd
12-5
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