ESA VT130W, Руководство по оборудованию, Страница: 630 / 976

CHAPTER 31
Communication ports
405.1200.037.2 - Rel.: 2.21 of 25/02/2008
31-2
All VTs communicate with other devices by means of serial and/or parallel
communication ports. We list on the following page the individual ports
with the respective type of communication and the function of the connec-
tion pins.
General notes
Serial communication is particularly prone to disturbances. To limit the influ-
ence of these disturbances it is necessary to use good quality shielded cables.
The table immediately below lists the characteristics of the cable we recom-
mend for serial connection.
Particular care should be taken in the choice and lay-out of cables,
specially with regard to the VT <-> Device connection serial cable.
Always:
• Find the shortest route
• Lay disturbed cables separately
Disconnect the power supply before connecting or disconnecting
the communication cables so as to avoid possible damage to the
VT and/or the connected device.
Necessary
steps
To have the communication ports (MSP, ASP, ASP-9 or ASP-8) function-
ing properly, certain pins on the VT side need to be jump-connected. The
ASP-15L port requires no jumpers.Which pins need to be connected
depends on which communication standard is to be used (RS232, RS422,
RS485 or C.L.TTY-20mA).
Specifications of serial connection cable
Direct current resistance Max. 151 Ohm/Km
Capacity coupling Max. 29pF/m
Shielding > 80% or total
Table 31.1: Jumpers to be effected inside the communication cable.
Signal
Pin number Communication standard
MSP ASP-8 ASP-9 ASP RS232 RS422 RS485 C.L.a C.L.p
RTS OUT 4 4 7 10
2 2 2 2 2
CTS IN 5 5 8 11
IKR OUT (C.L.) 15
1 1 1
RX+ IN (C.L.) 18
Signal GND 7
1 1 1 1
RX- IN (C.L.) 25
TX- OUT (C.L.) 11
Notes:
1 - Jumpers always to be effected.
2 - Jumpers to be effected only if the corresponding signals are not handled by the device connected to the VT.
C.L.a - Current Loop (Activ VT), C.L.p - Current Loop (Passive VT)