PSM-ME-RS232/RS485-P
Interface converter for RS-232 to RS-485 2-/4-wire or RS-422
1. Short Description
The PSM-ME-RS232/RS485-P rail-mountable and
compact interface converters have been designed
especially for industrial use in the switch cabinet or
switch box. They convert the RS-232 interface signals
bidirectionally to the RS-485 2-/4-wire and RS-422
standard.
The devices are simply snapped onto standard EN
mounting rails and supplied with 24 V DC or AC.
Their particular feature is the multifunctional
application:
– RS-232 master interface in RS-485 bus systems
– Networking RS-232 equipment
– RS-232 range increase to 1000 m as interferencefree and fast point-to-point connection
– RS-232 interface adaptation to RS-422 and RS-485
systems
The following features of the interface converter are
particularly outstanding:
– 3 operating modi can be configured
- RS-232 ↔ RS-485-2-wire
- RS-232 ↔ RS-485-4-wire
- RS-232 ↔ RS-422
– Can be used universally in all common bus systems
with UART/NRZ data format and 10/11 bits character
length
– Transmission rate can be set between 4.8 kbit/s and
115.2 Mbit/s
– Automatic transmit/receive changeover
– High-quality 3-way isolation
(VCC // RS-232 // RS-485)
– Integrated surge voltage protection with transient
discharge to the mounting rail
– Supply voltage of 24 V DC or AC to suit the switch
cabinet
– Minimal current consumption/power dissipation
If you have any technical questions, please contact us at:
PSM-HOTLINE:+49/(0)52 35/3-19890
FAX:+49/(0)52 35/3-19899
e-mail: interface-service@phoenixcontact.com
Headquarters: © Phoenix Contact GmbH & Co. KG • Flachsmarktstraße 8 • 32825 Blomberg • Germany
Phone +49-(0) 52 35-3-00 • Fax +49-(0) 52 35-3-4 12 00 • http://www.phoenixcontact.com
PSM-ME-RS232/RS485-P
Interface converter for RS-232 to RS-485 2-/4-wire or RS-422
1.1. Sample applications
RS-232
1
6
2
7
3
8
4
9
5
RS232
RS485
D(A) D(B) T(A) T(B)
6
GND
Fig. 2a
RS-232
1
6
6
2
2
7
7
3
3
8
8
4
4
9
9
5
5
PSM–ME–RS232/RS485–P
Ord.-No.: 27 44416
RS-485
PSM–ME–RS232/RS485–P
Ord.-No.: 27 44416
RS-232
1
RS232
RS232
RS485
RS485
D(A) D(B) T(A) T(B)
GND
D(A) D(B) T(A) T(B)
6
6
GND
Fig. 2b
1
PSM–ME–RS232/RS485–P
Ord.-No.: 27 44416
The RS-485 standard is specified for applications
with multipoint connections. We distinguish between
2-wire bus systems with half-duplex transmission and
4-wire bus systems with full-duplex transmission:
– RS-232 master adaptation (fig. 2a)
– Programming /and parameterizing connection
(fig. 2a)
– Networking RS-232 stations (the software must
guarantee that the stations can be addressed;
(fig. 2b)
RS-485
PSM–ME–RS232/RS485–P
Ord.-No.: 27 44416
1.1.1. RS-232 // RS-485 interface converter
6
2
7
3
8
4
9
5
RS232
RS485
D(A) D(B) T(A) T(B)
6
1
PSM–ME–RS232/RS485–P
Ord.-No.: 27 44416
GND
6
2
7
3
8
4
9
5
RS232
RS485
D(A) D(B) T(A) T(B)
6
1
6
2
7
3
8
4
9
5
PSM–ME–RS232/RS485–P
Ord.-No.: 27 44416
GND
RS232
RS485
D(A) D(B) T(A) T(B)
GND
6
max. 31 stations
1.1.2. RS-232 // RS-422 interface converter
6
2
7
3
8
4
9
5
PSM–ME–RS232/RS485–P
Ord.-No.: 27 44416
RS-422
1
The RS-422 interface is a balanced to earth interface
for point-to-point connections. The logical states are
represented by a differential voltage between two lines.
Areas of application are:
– Interface adaptation to RS-422 devices
(fig. 3a).
– Interference-free and fast point-to-point connection
up to 1000 m (fig. 3b)
RS-232
Fig. 2
RS232
RS485
D(A) D(B) T(A) T(B)
6
GND
fig. 3a
RS-232
6
6
2
2
7
7
3
3
8
8
4
4
9
9
5
5
RS232
1
1
PSM–ME–RS232/RS485–P
Ord.-No.: 27 44416
RS-422
PSM–ME–RS232/RS485–P
Ord.-No.: 27 44416
RS-232
RS232
RS485
RS485
D(A) D(B) T(A) T(B)
GND
6
D(A) D(B) T(A) T(B)
GND
6
Fig. 3b
Fig. 3
PHOENIX CONTACT page 2 of 12
PSM-ME-RS232/RS485-P
Interface converter for RS-232 to RS-485 2-/4-wire or RS-422
Type
2. Order data
Interface converter, for the conversion of
RS-232 to RS-485 2-/4-wire or RS-422,
with electrical 3-way isolation, rail-mountable
Order No.
Pcs.
Pkt.
PSM-ME-RS232/RS485-P
27 44 41 6
1
MCR-PS 230 AC/24 DC/650
MCR-PS 120 AC/24 DC/650
28 11 95 4
28 11 96 7
1
1
SUB-D9/SUB-D9
(socket/socket)
PSM-KA-9SUB 9/BB/2METER
27 99 47 4
1
SUB-D9/SUB-D25
(socket/socket)
PSM-KA-9SUB 25/BB/2METER
27 61 06 2
1
socket
pin
SUBCON 9/F-SH
SUBCON 9/M-SH
27 61 49 9
27 61 50 9
1
1
2.1. Accessories
Compact power supply, primary switchedmode, 24 V DC, 650 mA, rail-mountable
RS-232 cable, 2m, to connect the
PSM-ME converter
to a 9-pos. device interface
RS-232 cable, 2m, to connect the
PSM-ME converter
to a 25-pos. device interface
SUB-D plug, 9-pos., with screw
connection for free assembly of an
RS-232 cable
230 V AC
120 V AC
2.2. Technical Data
Supply voltage
Frequency
Rated current consumption
Connection
LED operational availability
24 V AC/DC ± 20 %
DC-60 Hz
typ. 85 mA
pluggable COMBICON screw terminal block
LED green
RS-232 interface
Type of transmission
Coding option
Data indicator
acc. to DIN 66 259 T1, CCITT V.28
transparent to protocol
DTE/DCE switchover via DIP switch
LED green (RD) RS-232 receive data (dynamic)
LED yellow (TD) RS-232 transmit data (dynamic)
4.8; 9.6; 19.2; 38.4; 57.6; 75; 93.75; 115.2
0...15 m shielded (recommended from 38.4 kbit/s, max.
5 m in industrial applications)
9-pos. SUB-D pin strip
Transmission rates in kbit/s
Transmission length
Connection
acc. to DIN 66 259-4
RS-485 2-wire, half duplex,
RS-485 4-wire, full duplex,
RS-422,
full duplex, can be configured via DIP switch
UART/NRZ1),
10/11 bit
11.5 bit after start bit edge
corresponding to the RS-232 interface
0...1200 m, twisted pair, shielded
either automatic control or control via RS-232 RTS/CTS
RTS/CTS ≥ 3V, transmit in direction of RS-485
Inversion possible via DIP switch
switchable, 390 Ω pull up/down, 150 Ω terminating resistance
pluggable COMBICON screw terminal block /shield connector
RS-485/RS-422 interface
Interface standards
Data format/coding
Character length
Tri-State
Transmission rates in kbit/s
Transmission length
Data direction switching
Terminating resistances
Connection
data/shield
3. General data
Protection circuit
Transient discharge
Electrical 3-way isolation
Test voltage
Resistance to vibration
Ambient temperature range
Protection type
Housing:
Material
Dimensions (W / H / D)
Connection data (conductor cross section)
- COMBICON plug connectors
Weight
Approval
Y-capacitors,
suppressor diodes, gas-filled surge arresters
via metal foot on EN mounting rail
power supply // RS-232 // RS-485/RS-422
2 kVrms, 50 Hz, 1 min.
5 g in acc. with IEC 68-2-6
0 °C to + 55 °C
IP 20
PA-V0
(99 / 22.5 / 118.6) mm
0.2 - 2.5 mm2 (AWG 24-12)
approx. 120 g
u
1) NRZ: Non Return To Zero
PHOENIX CONTACT page 3 of 12
PSM-ME-RS232/RS485-P
Interface converter for RS-232 to RS-485 2-/4-wire or RS-422
c
Complies with EMC guideline 89/336/EEC
EMC (electromagnetic compatibility)
Immunity to interference in acc. with EN 50082-2
• Electrostatic discharge (ESD)
EN 61000-4-2
Criterion B
8 kV discharge in air
6 kV contact discharge
• Electromagnetic HF field:
Amplitude modulation:
Pulse modulation:
EN 61000-4-3
Criterion A
10 V/m
10 V/m
• Fast transients (Burst)
Signal:
Supply:
EN 61000-4-4
Criterion B
2 kV/5 kHz
4kV/5 kHz
• Surge voltage capacities (Surge)
Signal:
Supply:
EN 61000-4-5
Criterion B
2 kV/12 Ω
0.5 kV/2 Ω
• Conducted disturbance
EN 61000-4-6
Criterion A
10 V
EN 55011
Class A
Noise emission in acc. with EN 50081-2
EN 61000 corresponds to IEC 1000
EN 55011 corresponds to CISPR11
Criterion A: Normal operating behavior within the defined limits.
Criterion B: Temporary impairment of operational behavior that the device corrects itself.
Class A: Area of application: industry, without special installation measures.
22,5
118,6
99
Fig. 4
PHOENIX CONTACT page 4 of 12
PSM-ME-RS232/RS485-P
Interface converter for RS-232 to RS-485 2-/4-wire or RS-422
Function elements (fig. 5)
1 Supply voltage 24 V AC/DC
4
5
2 LED Supply voltage (VCC)
S
48
5-
P
3 LED-RS-232 receive data (RD)
3 2
32
/R
1
5 RS-232 interface connection
Or SM
d.Nr. -M
:2 E
74 44 R
16 S
2
4 LED-RS-232 transmit data (TD)
P
6
RS
23
RS
5
A)
48
T(
B)
D( ND
A) G
2
D(
6 RS-485/RS-422 interface connection
B)
T( 6
7 Shield connector
D
(A
)
-P
85
S4
D
(B
)
T
(B
)
Device-Typ
RS232
/R
32
S2 1 6
-R 4 4
ME 4
M- : 27
PS -Nr.
t.
r
A
DTE
8 Snap-on foot for mounting rails in acc. with
DIN EN 50 022
T
(A
)
ON
8
4
ON
RS422
RS485 4-WIRE
RTS/CTS INVERS
RTS/CTS-CONTROLLED
OFF
RS485
RS485 2-WIRE
RTS/CTS STANDARD
SELF-CONTROLLED
N /
NE N
IO E
AT ION
OB AT
PR OB
APPPR
A
DIP-Switch
3
2
7
/
1
6
OFF OFF
ON
ON
4,8
ON
OFF ON
ON
9,6
OFF
OFF ON
ON
19,2
OFF OFF ON
ON
38,4
OFF OFF OFF
ON
57,6
ON
ON
OFF ON
75
OFF
ON
OFF ON
93,75
OFF ON
OFF ON
115,2
FUNC.
5
7
SPEED
(kbit/s)
DCE
6
OFF
Terminate
RS485/RS422
G
N
D
S
AL S
OV AL
PR OV
APPPR
A
8
Fig. 5
4. Operational Diagram
24V
24V
OV
OV
RS - 232
DCE
DTE
TxD
3
RxD
2
RTS
7
CTS
8
GND
5
DSR
6
DTR
4
2 Wire
O FF
DIP 7
gn
DIP 6
O N (RTS / CTS)
O FF (RTS / CTS)
ON
4 Wire
ye
ON
D(A)
D(B)
DIP 8
O FF (RS 485)
O N (RS 422)
O FF
DATA
DIP 5
+5V
T(A)
T(B)
Bus - Management
2 Wire / 4 Wire
gn
RS - 485
RS - 422
+5V (Port A)
390Ω 150Ω 390Ω
+5V (Port B)
390Ω 150Ω 390Ω
VCC
+5V
+5V
SUB - D 9
pole
Steckbare Schraubklemme
Screw terminal block
Bloc de jonction a`vis
Borne de tornillo
RATE
GND
Shield
Fig. 6
PHOENIX CONTACT page 5 of 12
PSM-ME-RS232/RS485-P
Interface converter for RS-232 to RS-485 2-/4-wire or RS-422
5. Notes on connection
24 V
1
5.1. Connections (fig. 7)
0V
1 Plug connector power supply
Connect 24 V AC/DC ± 20 % via the COMBICON
plug connector (PIN 1 and 3). Operational availability
is signaled via the VCC LED 2.
2
3
7
3
8
4
9
5
4 RS-485/RS-422 interface
pluggable COMBICON screw terminal block
1
3 RS-232 interface
9-pos. SUB-D pin strip
6
PSM–ME–RS232/RS485–P
Ord.-No.: 27 44416
2
RS232
RS485
D(A) D(B) T(A) T(B)
6
GND
4
Fig. 7
Or SM
d.Nr. -M
:2 E
74 44 R
16 S
2
32
/R
S
48
5-
P
5.2. Mounting in the switch cabinet (fig. 8)
P
Mounting (on 35 mm mounting rails in acc. with
DIN EN 50 022):
Hinge the device into the upper edge of the mounting
rail and snap it in with a downward motion.
RS
23
RS
5
A)
48
T(
B)
D( ND
A) G
2
D(
B)
T( 6
D
(A
)
-P
85
D
(B
)
T(A
)
DTE
ON
Note: The mounting rail must be
connected to ground potential. This is the
only way to guarantee that the integrated
surge voltage protection functions and
that the shield of the bus conductor
makes contact effectively.
SPEED
(kbit/s)
6
DCE
G
N
D
1
6
7
8
4
ON
RS422
RS485 4-WIRE
RTS/CTS INVERS
RTS/CTS-CONTROLLED
DIP-Switch
3
2
FUNC.
5
SELF-CONTROLLED
OFF OFF
ON
ON
4,8
ON
OFF ON
ON
9,6
OFF
OFF ON
ON
19,2
OFF OFF ON
ON
38,4
OFF OFF OFF
ON
57,6
ON
ON
OFF ON
75
OFF
ON
OFF ON
93,75
OFF ON
OFF ON
115,2
OFF
Terminate
RS485/RS422
RS485
RS485 2-WIRE
OFF
S
AL
OV LS
PR VA
AP PRO
/
P
N / A
E
N
IO EN
AT N
OB TIO
PR BA
AP PRO
AP
RTS/CTS STANDARD
Dismantling:
Pull back the metal disassembling lever 1 with the
aid of a screwdriver and remove the device from the
top.
Device-Typ
RS232
S4
/R
32
S2 41 6
E-R 44
M-M: 27
PS.-Nr.
rt
A
T(B
)
1
Fig. 8
PHOENIX CONTACT page 6 of 12
PSM-ME-RS232/RS485-P
Interface converter for RS-232 to RS-485 2-/4-wire or RS-422
6. The RS-232 interface
peripherals side
PSM-ME-RS232...
Designation
SUB-D 9-pos.
Transmit data
Receive data
Clear to send
Request to send
Functional ground
DEE data terminal ready
Data set ready
Ground
TXD
RXD
CTS
RTS
GND
DTR
DSR
6
(pin)
PIN 3
PIN 2
PIN 8
PIN 7
PIN 5
PIN 4
PIN 6
Shield
SUB-D 9-pos.
(pin)
SUB D
25
9
Max.
15 m
TxD
RxD
CTS
RTS
DTR
DSR
GND
6
3
2
8
7
4
6
5
3
2
8
7
4
6
5
TxD
RxD
CTS
RTS
DTR
DSR
GND
2
3
5
4
20
6
7
6.1. Interface coupling
Make a 1-to-1 connection between the PSM module
and the peripheral device as shown in Fig. 9.
Fig. 9
S
48
5-
P
Note: For a minimum configuration, you need to
connect TXD, RXD and GND (software handshake)!
Connect the 9-pos. SUB-D plug to the module
(fig.10).
P
S
OOrrd M
d.-.-N Nr.r.: M
: 227 E
7 444 -R
4 441 S
166 2
32
/R
6.2. Data indicator
RS
23
RS
48
A
T(
B)
D( ND
A) G
2
D(
)
5
Two diagnostic LEDs indicate the RS-232 interface
modes
– Yellow: Transmit data (TD), dynamic
– Green: Receive data (RD), dynamic
B)
T( 6
-P
D
(A
)
85
D
(B
)
T
(A
)
S4
/R
32
S2 41 6
E-R 44
M-M: 27
PS.-Nr.
Art
T
(B
)
Device-Typ
RS232
DTE
ON
SPEED
(kbit/s)
DCE
6
7
8
RS422
RS485
RS485 2-WIRE
OFF
RTS/CTS STANDARD
SELF-CONTROLLED
/
4
ON
RS485 4-WIRE
RTS/CTS INVERS
RTS/CTS-CONTROLLED
/
DIP-Switch
3
2
6
N
NE N
IO NE
ATTIO
OBBA
PRRO
APPP
A
1
FUNC.
5
OFF OFF
ON
ON
4,8
ON
OFF ON
ON
9,6
OFF
OFF ON
ON
19,2
OFF OFF ON
ON
38,4
OFF OFF OFF
ON
57,6
ON
ON
OFF ON
75
OFF
ON
OFF ON
93,75
OFF ON
OFF ON
115,2
OFF
Terminate
RS485/RS422
G
N
D
S
ALLS
OVVA
PRRO
APPP
A
Fig. 10
6.3. Configuration
S2
32
/R
74
44
16
E-R
Or
d.-
PS
M
M-
:2
2
Nr.
For configuration, release the top of the housing on
both sides 1. Pull the p.c.b. out of the housing as far
as possible 2 (fig. 11).
RS
Static charges can damage electronic
devices.
Discharge the electrical charge from your
body before opening and configuring the
device.
To do so, touch a grounded surface, e.g.
the metal housing of the switch cabinet.
23
RS
48
A
T(
B)
D( ND
A) G
2
D(
)
5
B)
T( 6
D
(A
)
D
(B
)
T(
A
)
T(
B
)
ON
6
OFF
1
Terminate
RS485/RS422
G
N
D
FUNC.
5
6
7
8
ON
RS422
RS485 4-WIRE
RTS/CTS INVERS
RTS/CTS-CONTROLLED
OFF
RS485
RS485 2-WIRE
RTS/CTS STANDARD
SELF-CONTROLLED
IO
AT
OB TIO
PR BA
AP PRO
P
Fig. 11
PHOENIX CONTACT page 7 of 12
PSM-ME-RS232/RS485-P
Interface converter for RS-232 to RS-485 2-/4-wire or RS-422
6.4. DTE/DCE switchover (fig. 12)
DTE/DCE
The DTE/DCE slide switches can be used to cross
the cables TXD and RXD as well as RTS and CTS
internally so that an adaptation to DTE or DCE
interfaces can be performed easily.
ON
DTE
For the connection to:
– Data terminal equipment (DTE) → switch to position
DTE.
(Standard setting for most applications)
ON 10
9
8
7
6
5
PSM-ME-RS232/RS485-P
Art.-Nr.: 27 44 41 6
DCE
Device-Typ
RS232
DTE
OFF
Terminate
RS485/RS422
P
ON
1
2
3
OFF
4
DIP-Switch
(kbit/s)
SPEED
OFF
ON
OFF
ON
OFF
ON
RTS/CTS STANDARD
SELF-CONTROLLED
ON
RS485
RS485 2-WIRE
ON
OFF
ON
ON
OFF
RTS/CTS-CONTROLLED
ON
ON
OFF
OFF
ON
ON
OFF
RTS/CTS INVERS
OFF
OFF
OFF
OFF
ON
ON
ON
RS422
RS485 4-WIRE
ON
ON
ON
ON
OFF
OFF
OFF
5
4,8
9,6
19,2
38,4
57,6
75
93,75
115,2
6
7
8
FUNC.
If the connected interface type is unknown, you can
determine the right configuration by trial and error
(DTE/DCE switch).
ON
– Data communication equipment (DCE) → switch to
position DCE.
ON 410
3
2 9
1
8
7
6
5
4
3
2
1
APPROBATIONEN / APPROVALS
Fig. 12
6.5. CTS/RTS support (DIP switch 5)
In normal operating mode, no control lines (RTS/
CTS) are required for data direction switching (switch
position DIP 5 "OFF").
The data direction switching can alternatively be
controlled through the RTS/CTS lines. Set the DIP
switch 5 to the "ON" position.
6.6. RTS/CTS inversion (DIP switch 6)
In uncommon applications, the control lines must be
inverted. Set the DIP switch 6 to the "ON" position
(default: "OFF"). The signal position in inverse mode is
then as follows:
RS - 232
Function:
RTS/CTS –3 V to –15 V = RS-485 receive mode
RTS/CTS +3 V to +15 V = RS-485 transmit mode
DCE
DTE
TxD
3
RxD
2
RTS
7
CTS
8
GND
5
DSR
6
DTR
4
RTS/CTS +3 V to +15 V = RS-485 receive mode
RTS/CTS -3 V to -15 V = RS-485 transmit mode
PHOENIX CONTACT page 8 of 12
DIP 6
DATA
S1
O N (RTS / CTS)
O FF (RTS / CTS)
Bus - Man
RATE
Fig. 13
PSM-ME-RS232/RS485-P
Interface converter for RS-232 to RS-485 2-/4-wire or RS-422
7. The RS-485/RS-422 interface
D(A)
D(B)
GND
Pin configuration
Designation
COMBICON
Data line (+)
Data line (–)
Signal ground
Ground/shielded connection
D(B)
D(A)
GND
6
1
PSM-ME-RS-485
7.1. Operation as RS-485 2-wire interface
(pin)
PSM-ME-RS-485
1
2
6
6
1
2
6
6
PIN 2
PIN 1
PIN 6
PIN 8
D(A)
D(B)
GND
Shield
COMBICON
Fig. 14
Settings:
1) As described in the section "RS-232 interface", set the operating mode of the RS-232
interface with DIP switch 5 and 6 and
the type of interface with the DTE/DCE
switchover switch.
DTE/DCE
RS-485 Terminate
ON
DTE
Note: If automatic operating mode
is selected, no control lines from the
RS-232 interface are required.
ON 10
9
8
7
6
5
ON 410
3
2 9
1
8
7
6
5
4
3
2
1
PSM-ME-RS232/RS485-P
Art.-Nr.: 27 44 41 6
DCE
Device-Typ
RS232
DTE
OFF
Terminate
RS485/RS422
ON
P
ON
ON
1
ON
2
OFF
3
DIP-Switch
(kbit/s)
SPEED
Fig. 15
O
R
ON
ON
OFF
OFF
ON
ON
OFF
RTS/CTS
SELF-CO
RS485 2-
OFF
OFF
OFF
OFF
ON
ON
ON
ON
RS422
RTS/CTS-CONTROLLED
RTS/CTS INVERS
RS485 4-WIRE
ON
ON
ON
ON
OFF
OFF
OFF
6
7
8
FUNC.
5
4,8
9,6
19,2
38,4
57,6
75
93,75
115,2
2) If the automatic operating mode was selected,
set the transmission rate with the aid of DIPswitches S1-S4 (fig. 15) and the table
below.
All PSM converters and bus stations must
be set to the same transmission rate!
RS
T(
)
(B D
GN
5
A)
48
B)
T( 6
The interface converters only convert an electric
signal.
D
(A
)
D
(B
)
T
(A
)
3) Set DIP switch 8 to position "OFF" to activate the
RS-485 operating mode.
T
(B
)
ON
4) Set DIP switch 7 to "OFF" to activate the 2-wire
mode.
6
7
ON
RS48
RTS/CT
Use shielded twisted pair cables.
Connect the cable shield to both sides of
the transmission path!
OFF
8
The data cables are shielded using a shield terminal
block that is fixed in the 6 terminal block (fig. 16). The 6
terminal block is connected capacitively to the
mounting rail contact on the underside of the device.
The shield connector is included in the scope of
delivery.
RTS/CTS-C
Fig. 16
SPEED
(kbit/s)
4,8
Shielding the data cables
115,2
6
6) To couple two RS-485 interfaces, connect the
connections acc. to fig. 14. (1 = twisted pair)
GND connection is recommended, but is not
essential.
FUNC.
5
5) If necessary, activate the terminating resistors
fig. 15 (Please observe the section 8 on
"Terminating resistor for the RS-485/RS-422
interface", page 12).
OFF
Terminate
RS485/RS422
G
N
D
DIP
1
2
3
4
ON
ON
OFF
OFF
9.6
ON
OFF
ON
ON
19.2
ON
OFF
ON
OFF
38.4
ON
OFF
OFF
ON
57.6
ON
OFF
OFF
OFF
75
OFF
ON
ON
ON
93.75
OFF
ON
ON
OFF
OFF
ON
OFF
ON
115.2
FUNC.
DIP
ON
OFF
5
RTS/CTS-CONTROLLED
SELF-CONTROLLED
6
RTS/CTS INVERS
RTS/CTS STANDARD
7
RS485 4-WIRE
RS485 2-WIRE
8
RS422
RS485
PHOENIX CONTACT page 9 of 12
PSM-ME-RS232/RS485-P
Interface converter for RS-232 to RS-485 2-/4-wire or RS-422
7.2. Operation as RS-485 4-wire interface
PSM-ME-RS-485
Pin configuration
Designation
COMBICON
Receive data (+)
Receive data (–)
Transmit data (+)
Transmit data (–)
Signal ground
Ground/shielded connection
D(B)
D(A)
T(B)
T(A)
GND
6
(pin)
D(B)
D(A)
T(B)
T(A)
GND
PIN 2
PIN 1
PIN 4
PIN 3
PIN 6
PIN 8
1
PSM-ME-RS-485
2
1
4
3
6
2
1
4
3
6
6
6
D(B)
D(A)
T(B)
T(A)
GND
Shield
COMBICON
Settings:
Fig. 17
1) Set as described in the section "RS-232 interface" the operating mode of the RS-232
interface using DIP switch 5 and 6 and
the type of interface with the DTE/DCE
switchover switch.
DTE/DCE
RS-485 Terminate
ON
DTE
Note: If automatic operating mode
is selected, no control lines from the
RS-232 interface are required.
ON 10
9
8
7
6
5
2) If the automatic operating mode was selected,
set the transmission rate with the aid
of DIP-switches S1-S4 (fig. 18) and the table
below.
PSM-ME-RS232/RS485-P
Art.-Nr.: 27 44 41 6
DCE
Device-Typ
RS232
DTE
OFF
Terminate
RS485/RS422
ON
ON
ON
1
ON
2
OFF
3
DIP-Switch
(kbit/s)
SPEED
Fig. 18
O
R
ON
ON
OFF
OFF
ON
ON
OFF
RTS/CTS
SELF-CO
RS485 2-
OFF
OFF
OFF
OFF
ON
ON
ON
ON
RS422
RTS/CTS-CONTROLLED
RTS/CTS INVERS
RS485 4-WIRE
ON
ON
ON
ON
OFF
OFF
OFF
6
7
8
4,8
9,6
19,2
38,4
57,6
75
93,75
115,2
FUNC.
5
All PSM converters and bus stations must
be set to the same transmission rate!
P
ON 410
3
2 9
1
8
7
6
5
4
3
2
1
)
B)
T( 6
D
(A
)
D
(B
)
T
(A
)
3) Set DIP switch 8 to position "OFF" to activate the
RS-485 operating mode.
T
(B
)
P
A
ON
4) Set DIP switch 7 to "ON" to activate the 4-wire
mode.
6
93,75
115,2
7
ON
ON
RS
RS485 4-WIR
RTS/CTS INVE
OFF
8
RTS/CTS-CONTR
Use shielded twisted pair cables.
Connect the cable shield to both sides of
the transmission path!
6
The data cables are shielded using a shield terminal
block that is fixed in the 6 terminal block (fig. 19).
The 6 terminal block is connected capacitively to the
mounting rail contact on the underside of the device.
The shield connector is included in the scope of
delivery.
FUNC.
5
Shielding the data cables
OFF
Terminate
RS485/RS422
G
N
D
5) If necessary, activate the terminating
resistors fig.18 (Please observe the section 8 on
"Terminating resistor for the RS-485/RS-422
interface", page 12).
6) To couple two RS-48 interfaces, connect the
connections acc. to fig. 17. (1 = twisted pair)
When connecting the device, take into account
that it is necessary to cross transmitted and
received data.
GND connection is recommended, but is not
essential.
5
The interface converters only convert an electric
signal.
Fig. 19
SPEED
(kbit/s)
4,8
DIP
1
2
3
4
ON
ON
OFF
OFF
9.6
ON
OFF
ON
ON
19.2
ON
OFF
ON
OFF
38.4
ON
OFF
OFF
ON
57.6
ON
OFF
OFF
OFF
75
OFF
ON
ON
ON
93.75
OFF
ON
ON
OFF
OFF
ON
OFF
ON
115.2
FUNC.
DIP
ON
OFF
5
RTS/CTS-CONTROLLED
SELF-CONTROLLED
6
RTS/CTS INVERSE
RTS/CTS STANDARD
7
RS485 4-WIRE
RS485 2-WIRE
8
RS422
RS485
PHOENIX CONTACT page 10 of 12
PSM-ME-RS232/RS485-P
Interface converter for RS-232 to RS-485 2-/4-wire or RS-422
7.3. Operation as RS 422 interface
Pin configuration
Designation
COMBICON
(pin)
1
PSM-ME-RS-422
Receive data (+)
Receive data (–)
Transmit data (+)
Transmit data (–)
Signal ground
Ground/shielded connection
D(B)
D(A)
T(B)
T(A)
GND
6
PIN 2
PIN 1
PIN 4
PIN 3
PIN 6
PIN 8
D(B)
D(A)
T(B)
T(A)
GND
PSM-ME-RS-422
2
1
4
3
6
D(B)
D(A)
T(B)
T(A)
GND
2
1
4
3
6
6
6
Settings:
Shield
COMBICON
1) Set the DIP switch 8 to position.
"ON" to activate the RS-422 operating mode
(fig. 21).
2) Set as described in the section "RS-232 interface" the interface type of the RS-232 interface
with the DTE/DCE switchover switch.
Note: In this operating mode, no
control lines from the RS-232 interface are
required and none are transmitted.
Fig. 20
RS-422 Terminate "ON"
DTE/DCE
3) Switch the line terminating resistor on both sides
of the RS422 transmission link on. ➞ Put
"Terminate" slide switch to "ON".
ON
DTE
4) To couple two RS-422 interfaces, connect the
connections acc. to fig. 20. (1 = twisted pair)
When connecting the device, take into account
that it is necessary to cross transmitted and
received data.
GND connection is recommended, but is not
essential.
ON 10
9
8
7
6
5
DIP 8
ON 410
3
2 9
1
8
7
6
5
4
3
2
1
PSM-ME-RS232/RS485-P
Art.-Nr.: 27 44 41 6
DCE
Device-Typ
RS232
DTE
OFF
Terminate
RS485/RS422
ON
P
ON
1
2
3
OFF
4
DIP-Switch
(kbit/s)
SPEED
OFF
ON
OFF
ON
OFF
ON
RTS/CTS STANDARD
SELF-CONTROLLED
ON
RS485
RS485 2-WIRE
ON
OFF
ON
ON
OFF
RTS/CTS-CONTROLLED
ON
ON
OFF
OFF
ON
ON
OFF
RTS/CTS INVERS
OFF
OFF
OFF
OFF
ON
ON
ON
RS422
RS485 4-WIRE
ON
ON
ON
ON
OFF
OFF
OFF
5
4,8
9,6
19,2
38,4
57,6
75
93,75
115,2
6
7
8
FUNC.
APPROBATIONEN / APPROVALS
Fig. 21
RS
Shielding the data cables
23
RS
48
A
T(
B)
D( ND
A) G
2
D(
)
5
B)
T( 6
D
(A
)
D
(B
)
T
(A
)
M
MPS.-N
t
Ar
T
(B
)
ON
The data cables are shielded using a shield terminal
block that is fixed in the 6 terminal block (fig. 22). The
6 terminal block is connected capacitively to the
mounting rail contact on the underside of the device.
The shield connector is included in the scope of
delivery.
6
57,6
75
93,75
115,2
6
7
8
ON
RS422
RS485 4-WIRE
RTS/CTS INVERS
RTS/CTS-CONTROLLED
OFF
RS485
RS485 2-WIRE
RTS/CTS STANDARD
SELF-CONTROLLED
OFF OFF OFF
ON
ON
ON
OFF ON
OFF
ON
OFF ON
OFF ON
OFF ON
FUNC.
5
Use shielded twisted pair cables.
Connect the cable shield to both sides of
the transmission path!
OFF
Terminate
RS485/RS422
G
N
D
/
N /
NE N
IO E
AT ION
B
O AT
A
Fig. 22
PHOENIX CONTACT page 11 of 12
PSM-ME-RS232/RS485-P
Interface converter for RS-232 to RS-485 2-/4-wire or RS-422
6
6
2
2
7
7
3
3
8
8
4
4
9
9
5
5
PSM–ME–RS232/RS485–P
Ord.-No.: 27 44416
1
1
A connectable line terminating resistor is integrated
in the converter and it must be switched on or off,
depending on the application.
PSM–ME–RS232/RS485–P
Ord.-No.: 27 44416
8. Set the line terminating resistor
correctly in RS-485 and RS-422 mode.
RS232
RS232
RS485
RS485
D(A) D(B) T(A) T(B)
D(A) D(B) T(A) T(B)
6
GND
6
GND
6
2
7
3
8
4
9
5
RS-485 is the standard for a multi-point-capable
connection (up to 32 terminals).
The RS-485 bus line may only be terminated at the
two most distant bus ends.
➞ "Terminate" slide switch to "ON"
at the beginning and end of the bus line
(fig. 23).
1
PSM–ME–RS232/RS485–P
Ord.-No.: 27 44416
8.1. In RS-485 mode (2/4-wire)
RS232
RS485
D(A) D(B) T(A) T(B)
6
GND
= Bus terminating resistor "ON"
Fig. 23
2
2
7
7
3
3
8
8
4
4
9
9
5
5
RS232
RS485
RS485
D(A) D(B) T(A) T(B)
6
GND
6
= Terminating resistor "ON"
Fig. 24
http://www.phoenixcontact.com
GND
RS 485/RS 422 Terminate
ON
DTE
ON
DTE
DTE
Device-Typ
RS232
DCE
OFF
Terminate
RS485/RS422
ON
TNR: 5104422-01
PSM-ME-RS232/RS485-P
Art.-Nr.: 27 44 41 6
ON 10
9
8
7
6
5
4
3
2
1
S
FU
Fig. 25
PHOENIX CONTACT page 12 of 12
30.07.99
D(A) D(B) T(A) T(B)
 PHOENIX CONTACT
PSM–ME–RS232/RS485–P
Ord.-No.: 27 44416
6
6
RS232
1
1
RS-422 is the standard for a point-to-point connection between two devices. The line terminating resistor
on both sides of the RS-422 transmission link must be
switched on.
➞ "Terminate" slide switch always in "ON" position
(fig. 24).
PSM–ME–RS232/RS485–P
Ord.-No.: 27 44416
8.2. In RS-422 mode