P300H
P300 Modem Installation and Operating Handbook
Page 168
Interconnecting Devices Using RS485
This page summarises the RS485 M&C ports of many different equipments from multiple vendors and explains how to interconnect them all for M&C operation.
Connect any of the following devices in parallel on a daisy chain cable for multi-device operation:
Product:
Paradise
Paradise
Paradise
Paradise
Paradise
Codan
Anancom
Gilat
Signal
P300 / P400
P300
P500
P200 / P230 / P230DI
P1300 / P1301
C57/5900
AnaSat-C
SkyWay
Port Name:
Remote
ESC/Aux/
Async
RS485
RS485
RS485/
ESC Async
Rem
Async 2 on
Monitor/
M & C
Maint
M&C
Back' Alm
ESC
In
Out
RS232
Cont
P1361
Control
Connector: 9 pin `D`
50 pin `D` 15 pin `D`
9 pin `D`
9 pin `D`
15 pin `D`
9 pin `D`
15 pin
9 pin `D`
9 pin `D`
18p Circ'
9 pin `D`
(on cable)
Male
Male
Male
Male
Female
Male
Male
`D` Male
Male
Male
Female
Male
Shield
1
1
1
5
5
14
9
12
3
5
12 and 18
1
Master-A (to product `-`)
9
13 / (15)
2 / (3)
1
1
1
2 / (7)
1
9 / (5)
7
11
5
1
1
1
1
Master-B (to product `+`)
3
14 / (16)
9 / (10)
6
6
9
3 / (5)
9
2 / (8)
3
10
9
1
1
1
1
Slave-A (from product `-`)
6
15 / (13)
3 / (2)
2
2
2
7 / (2)
2
5 / (9)
8
9
3
2
1
1
1
1
Slave-B (from product `+`)
4
16 / (14)
10 / (9)
7
7
10
5 / (3)
10
8 / (2)
2
8
7
2
1
1
1
1
Conn' Ref'
A
P / (Q)
R / (S)
D
E
F
G / (H)
I
J / (K)
L
N
T
3
1
1
1
1
Notes
1: For all Async ESC channels carrying M&C data (for distant end M&C via the satellite) the cabling depends on which end of each separate M&C link the device is. Devices routing M&C data to the
satellite are considered to be at the Local end of the M&C link, and devices bringing M&C into a site from the satellite are considered the Remote end of the link. For example at a Hub co-located with
the system M&C computer every device would be considered the `Local end` of any M&C links via satellite. However at a node the device providing the incoming M&C link from the satellite would be considered
the `Remote end` of the link, but any additional devices taking the M&C back to the satellite on a second hop to a more distant station would be the `Local end` again (local because they are the end of
that specific link nearest the M&C computer). Pin numbers for Async ESC ports in the table above are shown as: “local end pin / (remote end pin)”, and the cable must be made accordingly taking into
1
account which end of each M&C link the particular ESC connector is. For user convenience the P300 & P400 can provide an internal link from the M&C port to ESC port, avoiding having to cable M&C to
both the M&C connector and then the ESC connector (if distant end control via satellite is to be used). When using this internal link you set the ESC interface to `Link to M&C` on the modem, and specify
whether it is `Local end` or `Remote end` and the device internally routes it correctly (without any pin number changes on the Remote M&C port).
2. For reliable operation ensure that when no slave devices are talking the Slave-B line floats at least 200-300mV higher than the Slave-A line. If necessary provide 1k, 470
6
, or even 220
6
pullups (Slave-B
to RS232/485 converter DC+) and pulldowns (Slave-A to Gnd) to ensure lines float as specified. This ensures idle state of slave lines when not driven is a `mark` as an idle state of `space` will cause the
first and possibly subsequent characters of slave responses to be lost. Due to the low speeds & short cables it is not normally required to terminate RS485 async M&C cables. If it does prove necessary
use 120
6
between Master-A and Master-B at the end of the cable (furthest from bus controller). Between Slave-A and Slave-B try 470
6
first farthest away from the controller, then add 470
6
at the controller
end too. If necessary reduce both to 240
6
or even 120
6
.
3. Conn' Ref' is used for specifying cables. For example a cable to connect a P300 at the distant end of a link with a Codan C5700 transceiver could be specified as: “A + 500cm + L” (ie connector `A`, 5 metres
of cable, then connector `L`). The 10 connector `local RS485 bus` daisy-chain cable used in a 1:N switch to connect a backup P300, the P500 `RS485 Out` port, and a further 8 P300's could be specified
as: “A + 50cm + E + 8 x (30cm + A)”.