Siemens 538-907 Installation Instructions

TTL/RS-485 Interface

Product Description

The TTL/RS-485 Interface is a TTL to RS-485 trunk
interface. It converts two-wire TTL level signals into
RS-485 signals for the network controller. No
internal settings are required for communication
speed (bps). The TTL/RS-485 Interface operates at
any required trunk speed. The TTL/RS-485 Interface
is supplied with a 120 Vac Hz wall plug-in power
pack with a 6-foot (1.8 meter) CD power cord.
CAUTION:
Use only the plug-in transformer shipped
with this device.
Product Numbers
538-907 TTL/RS-485 Interface 115V

Required Tools

•
Flat-blade screwdriver (1/8 inch blade width)
•
Wire strippers
CAUTION:
Always wear an electro-static discharge
wrist strap and discharge accumulated
static before touching field panel
components.
Expected Installation Time
20 minutes
Installation Instructions
Prerequisites
To comply with installations requiring
Class 1 conduit connections, you may
mount the TTL/RS-485 Interface in a field
panel enclosure.
For Console Top Installation
•
TTL source device in place; TTL cable
assembled and connected to source device
•
Source of transient protected 120 Vac 60
Hz available
•
Network controller installed and tested
For Wall-mounted Enclosure
•
Enclosure mounted
•
Transient protected outlet installed
•
Network controller installed and tested
Installation
1. Connect the TTL cable between the RS-485
Interface and the TTL source device. See the
TTL Interface side of the TTL/RS-485 Interface
for circuit polarity.
2. Maintain proper fit. If the TTL trunk contains a
shield, cut it flush with the cable jacket or tape it
back.
3. Connect the RS-485 Interface terminals to the
network controller.
4. Maintain polarity between the network controller
and the RS-485 connections. The shield should
be landed on the network controller, but taped
back at the RS-485 Interface connections.
The network controller installation is now complete.
Document No. 588-097
Rev. 1, July, 2002
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