And Rs-422/485 Cable - Honeywell MAXPRO-Net Hardware Installation Manual

9.5.3 RS-232 and RS-422/485 cable
The EIA RS-232 standard is an unbalanced signal transmission standard. This means
that the data signal levels (+10v or -10v DC) are inserted and measured with respect to
a single SIGNAL-GROUND wire, common to both the receive and transmit data wires.
This limits the distance over which it can reliably be used (approx. 30m at 19.2Kb on
100pF/m cable). Although lower capacitance cables can increase the distances
possible, caution should be observed with regard to earth loop potential difference
between the equipment.
Generally RS-232 direct wire connections should be restricted to equipment within the
same local area and powered from a common main power source (having the same
earth path).
Cable Type
Beldon 8723
The recommended cable has individually screened pairs in an aluminum-polyester
shield with a 24AWG stranded tinned copper drain wire. The cables are covered with a
PVC jacket. The wire conductors are polypropylene insulated providing a rating of 300V
o
at 60 c.
The EIA RS-422 and RS-485 standards use a balanced wire pair to send or receive data
signal levels (+5v and -5v DC). This means that the inserted signal is across the pair
and not with respect to ground. When measured at the receiving end it is the difference
across the wire pair that indicates the data bit being transferred. There can be AC or DC
potential difference to ground and not affect the recovery of the transferred data.
Cable Type
Beldon 9829
The recommended cable has individually screened pairs in an aluminum-polyester
shield with an overall tinned copper braid shield (65% coverage). The cable is covered
with a PVC jacket. The wire conductors are polypropylene insulated providing a rating
of 30V at 60
Rev. C
Number
Wire
of
Conductors
Pairs
22 Gauge
2 Stranded Tinned
copper (7x30)
Number
Wire
of
Conductors
Pairs
24 Gauge
2 Stranded Tinned
copper (7x32)
o
c. The nominal impedance of the cable is 100 ohms.
Nominal
Outside Capacitance pF/m
Diameter
(mm)
4.19
Nominal
Outside Capacitance pF/m
Diameter
(mm)
7.73
9-7
Nominal
(between
conductors)
116
Nominal
(between
conductors)
51
HMXMU001018
10/06