Toshiba Perception E Ex Digital Pbx Installation And Maintenance Manual

							INSTALLATlONlNSTRUCTlONS 
SECTION 200-255-204 
FEBRUARY1992 
FIGURE 4-38-INSTALLING DDIU-MAT 
Pin No. Designation 
1 FG Protective Ground/Frame 
2 SD Transmitted Data (to DDIU) 
3 RD Receive Data (from DDIU) 
4 RTS Request to Send (to DDIU) 
5 CTS Clear to Send (from DDIU) 
6 DSR Data Set Readv (from DDIU) 
1 7 1 SG 1 Sianal Ground/Common Return 
1 
1 8 (RCDI Receive Carrier Detect (from DDIU) 
1 
1 15 /ST21 Transmission Signal Element Timing 
(from DDIU) I 
, 7 RT Transmission Signal Element Timing 
(from DDIU) 
Data Terminal Ready/Equipment 
2o DTR Readv (to DDIU) 
I I < . 
22 1 Cl ) Ring Indicator (from DDIU) 
5.84 The provided 2-pair modular line cord con- 
nects the DDIU-MAT to the electronic telephone 
line connector. The 3-pair modular line connector 
connects to the 3-pair house cable run from the 
LCEC/NCEC (see Digital Data Interface Unit Con- 
nections, Paragraph 5.70). 5.85 Several DIP switches found on the bottom of 
the DDIU-MAT must be set for proper operation 
(Figure 4-39). 
DIP 
SWITCHES 
1 1 1 NO DATA 1 
1 2 1 2400 bps 1 
1 3 1 4800 bps 1 
1 4 / 9600 bps ) 
FIGURE 4-39-DDIU-MAT DIP SWITCHES 
5.86 When the DATA DETECTION switch (Switch 
1) is placed in the ON position, the automatic data 
release feature will be activated (data connection is 
automatically released if no data is transmitted for 
a period of 18 minutes). 
4-29  
						

							INSTALLATION INSTRUCTIONS 
SECTION 200-255-204 
FEBRUARY1992 
5.87 Switches 2,3, and 4 select the data speed for 
synchronous transmission only. 
Switch 2 = 2400 bps 
Switch 3 = 4800 bps 
Switch 4 = 9600 bps 
5.88 If asynchronous operation is used, the 
switches will have no effect and the data speed will 
self-adjust to a maximum speed of 19.2 kbps or 
less. 
5.89 A power ON/OFFswitch that appears on some 
early DDIU-MAT models controls power to the 
DDIU-MAT from the power supply. If the switch is 
OFF, the DDIU-MAT will not function, but the elec- 
tronic telephone will continue functioning normally. 
When the switch is ON, both DDIU-MAT and elec- 
tronic telephone are functional. In later models, the 
DDIU-MAT is operational when the power supply is 
plugged in. 
/MPORTANT! 
All connections to DDlUs (-MA or -MAT) 
must observe correct tip and ring polarity 
for proper operation. 
5.90 DDIU-MA 
5.91 The DDIU-MA is a stand-alone unit that incor- 
porates both the manual dialing and auto-answer- 
ing features of the DDIU-MAT, but is used as a data 
transceiver only. 
5.92 The DDIU-MA has several internal and ex- 
ternal switches that must be set for proper opera- 
tion. 
5.93 The power ON/OFF switch, on the bottom of 
the DDIU-MA, must be turned ON for the DDIU-MA 
to operate. When the switch is ON, an LED on the 
front faceplate will light. 
5.94 The DDIU-MA’s faceplate must be removed 
to set the internal DIP switches. Remove the face- 
plate by carefully lifting the lower right corner and 
then pulling the faceplate away from the base. Set 
the following parameters as required at switch S26 
on the internal DIUA PCB (Figure 4-40): Switch 1* = 
Equipment Ready Supervision 
ON-Data device provides an Equip- 
ment Ready signal to the DDIU (the 
Terminal Ready LED will light only 
when the signal is received). 
OFF-Data device does not provide an 
Equipment Ready signal to the DDIU 
(the Terminal Ready LED will remain 
lit continuously). 
Switch 2 = not used. 
Switch 3 = not used. 
Switch 4 = ON (Enables automatic answer mode of 
operation.) 
Switch 5 = ON (Activates Automatic Data Release 
feature. The data connection is auto- 
matically released if no data is transmit- 
ted for a period of 18 minutes.) 
Switch 6 = 2400 BPS ** 
Switch 7 = 4800 BPS ** 
Switch 8 = 9600 BPS ** 
*A data path cannot be established if the 
Terminal Ready light is OFF (even though a 
DDIU-MA can be answered manually). The 
Terminal Ready light must be ON to establish 
a data path when answering manually. 
**Select the appropriate speed for synchro- 
nous data transmission. If the asynchronous 
mode of operation is used, these switches, 
have no effectand the DDIU-MA willautomati- 
tally adjust to the appropriate speed (to a 
maximum of 19.2 kbps). 
5.95 Two switches on the DIUB PCB must be set 
for either DTE or MODEM (DCE) operation. The pin 
assignments shown in Paragraph 5.83 explain the 
RS-232C cable signaling differences between DTE 
and DCE devices. (Typically, a DTE is a terminal 
device such as a personal computer or printer, 
while a DCE is an intermediate device such as a 
modem or protocol converter connected to a host. 
Refer to the data device manufacturer’s documen- 
tation for its signaling information.) Set the DIUB 
PCB switches as follows: 
1) Loosen the two screws found under the DDIU- 
MA’s faceplate on the right side (top and 
bottom) of the DIUA PCB (Figure 4-40). 
4-30  
						

							LOOSEN 
I-  
LOOSEN’ 
FIGURE 4-40-DDIU-MA DNA PCB 
2) Carefully separate the two halves of the DDIU- 
MA to expose the S2 and S3 (DTE/MODEM) 
switches (Figure 4-41) in the upper left corner 
of the DIUB PCB. 
3) If the DDIU-MA is to be connected to a DTE, 
both switches must be in the DTE position. If 
it will be connected to a DCE, both switches 
must be in the MODEM position. 
4) Reassemble the DDIU-MA. 
5.96 See Operating Procedures or DDIU-MA and 
Electronic Telephone User Guides for information 
on the DDIU dialpad, LED/button operation and 
functions. 
INSTALLATION INSTRUCTIONS 
SECTlON200-255-204 
FEBRUARY1992 
s3 
-- FIGURE 4-41-DIUB P[;B 
5.97 The DDIU-MA requires three types of con- 
nections for proper operation: 
l Power supply (to facility power). 
l 25-pin female RS-232C connector (DDIU-MA to 
LCEC/NCEC). 
l Single-pair modular connector (DDIU-MA to 
LCEWNCEC). 
5.98 The power supply (provided) connects the 
DDIU-MA to a 117 VAC wail outlet. The 25pin 
female RS-232C connector connects to the cus- 
tomer-supplied data device and is configured for 
either DTE or DCE operation as follows: 
4-31  
						

							INSTALLATION INSTRUCTIONS 
SECTION 200-255-204 
FEBRUARY 
1992 
DTE Position: 
Pin No. Desianation 6. DIGITAL TELEPHONE STATION 
EQUIPMENT INSTALLATION 
1 FG Protective Ground/Frame 
2 SD Transmitted Data (to DDIU) 6.00 Digital Telephone Connections 
1 8 ( RD ) Receive Data (from DDIU) 
I 
4 RTS Request to Send (to DDIU) 
5 CTS Clear to Send (from DDIU) 
6 DSR Data Set Ready (from DDIU) 
7 SG Signal Ground/Common Return 
8 RCD Receive Carrier Detect (from DDIU) 
,5 ST2 Transmission Signal Element Timing 2 
(from DDIU) 
1 17 j RT 1 ~ ~ ____ ~~~ ~  Transmission Signal Element Timing 2 
(from DDIU) 1 
1 20 /DTRI Data Terminal Ready/Equipment 
Ready (to DDIU) 
I 
1 22 ( Cl 1 Ring Indicator (from DDIU) 
DCE (MODEM) Position: 
Pin No. 
Designation 
1 FG Protective Ground/Frame 
2 TD Transmitted Data (from DDIU) 
3 RD Receive Data (to DDIU) 
I 4 I RTS / Request to Send (from DDIU) I 
1 24 1 ST1 1 (to DDIU)  Transmit Signal Element Xming 1 
5.99 The DDIU-MA connects to the LCEC/NCEC 
with a single-pair station line cable that plugs into 
the modular connector on the back of the base (see 
Digital Data interface Unit Connections, Paragraph 
5.70). 
IMPORTANT! 
All connections to DDlUs (-MA or -MAT) 
must observe correct tip and ring polarity 
for proper operation. 6.01 See the DEKT Program in Section 200-255- 
300, Programming, for instructions on program- 
ming digital telephones. When installing digital 
telephones, digital DSSconsoles, PDIU-DI, or PDIU- 
DS, Version D.04 software or higher must be in- 
stalled. The system must be told the type of digital 
telephone (20-button, or 20-button with LCD) and 
what button assignment is required. 
6.02 Digital telephones are connected to the MDF 
via standard twisted-pair jacketed telephone cable. 
(Single-pair wiring is required; however, 2- or 3-pair 
wiring is strongly recommended to permit expected 
-distances for data, spare pair, etc.) To accommo- 
date the digital telephone line cord, terminate the 
cable in a modular station connector block (RJ25) 
at the station location. The standard modular digital 
telephone cord length is 7 feet (the maximum 
allowed length is 25 feet). 
6.03 The overall length of the digital telephone 
cable run from equipment cabinet to phone must 
not exceed 1,000 feet (305 M), 24 AWG cable. 
IMPORTANT! 
When installing the digital telephone cable, 
do not run parallel to and within 3 feet of an 
AC po wer line. Such power lines should be 
crossed at right angles (90”) only. 
6.04 Digital telephone connection details areshown 
in Figure 4-42. 
6.10 Digital Telephone Wall Mounting 
6.11 Both telephones are wall-mounted in the same 
manner, and they may be mounted on a wall or any 
other flat, vertical surface to which the base can be 
secured. When selecting the mounting site, con- 
sider the digital telephone’s weight and the addi- 
tional stresses to which the mounting will be sub- 
jected. 
4-32  
						

							INSTALLATION INSTRUCTIONS 
SECTIONZOO-255-204 
FEBRUARY1992 
NOTE: 
Digital Telephones with Data Interface Units (PDIU-DI) or Off-hook Cal/Announce (DVSU), and Stand- 
a/one Data Interface Units (PDIU-DS) are connected, per Figure 4-42, using single-pair wiring. 
NDKU PCB 
I PCB CONNECTOR 
26 
1 
27 
2 
28 
3 
29 
4 
30 
5 
31 
6 
-I TL4 I l 
DI ” I I I 32 I- 
I I La 
I 
-. - 1 34 l- 
I 
I I 
I I 37 
l-I 7 I I 
I k 12 
I I 
I 15 l- 
(W-BL) 
(BL-W) 
(W-0) 
(0-W) 
(W-G) 
G-W) 
(W-BR) 
(BR-W) 
W-S) - TLl 
- RLl 
- 
- TL2 
- RL2 IR 
(W) Y 
&Rl 8AUX 8R2 
MODULAR 
I STATION 
TAILCORD 
I 1 TO TELEPHONE #2 
ii;; 8’ f= j TOTELEPHONE#3  CROSS-CONNECT 
BLOCK 
MODULAR JACK 
(R-O) --+- TL4 
(0-R) I , RL4 
(R-G) I ! 
(G-R) ; ; 
1 
(R-BR) ! ; 
TL5 
P-R) 1 ; RL5 
P-3 
I , 
(S-W I I 
(BK-BL) ; ; 1 
TL6 
(BL-BK) ; i 
RL6 
(BK-0) I ’ 
(0-BK) [ ; 
I 
(BK-G) ! I 
TL7 
G-W 1 ; RL7 
(BK-BR) ; , 
I I 
(BR-BK) I ; 1 
(BK-S) I I 
TL8 
(S-BK) I ; 
RL8 
U-W 1 ; 
(BL-Y) 
I J 
1 
. 
 25-PAIR CABLE 
“J” CABLE CONNECTOR PINS TO TELEPHONE #4 
TO TELEPHONE #5 
TO TELEPHONE #6 
TO TELEPHONE #7 
TO TELEPHONE #8 
FIGURE 4-42-DIGITAL TELEPHONE CONNECTION 
4-33  
						

							INSTALLATION INSTRUCTIONS 
SECTION 200-255-204 
FEBRUARY 1992 
6.12 Loosen the four captive screws securing the 
digital telephone’s base, and remove the base 
(Figure 4-43). 
6.13 Using a cutter, remove the handset hanger 
from the base. Insert the handset hanger in the slot 
provided on the front of the telephone (Figure 4- 
44). The hanger fits in the notch on the handset. 
6.14 Rotate the mounting base 180” and secure to 
the telephone with the four captive screws (Figure 
4-45). 
6.15 Connect the electronic telephone to the wall 
modular connector with a short cord (approximately 
3 inch length). Route the cord into the hollow 
portion of the base, then mount the digital telephone 
on the wall mounting connector. Test each digital 
telephone using the 7TRM Program, Section 200- 
255-300, /=rogramming. 
6.20 Off-hook Call Announce 
6.21 The Off-hook Call Announce (OCA) feature 
enables a digital telephone to originate and receive 
HANDSET 
HANGER 
I PLASTIC 
TAB 
I-IbUKt 4-4Y-HtMUVAL Ul- 
DIGITAL TELEPHONE BASE FIGURE 4-44-REMOVAL OF HANDSET HANGER 
MOUNTING BASE FOR WALL-MOUNT INSTALLATION 
voice announcement when the station’s handset is 
off-hook. Standard telephones can originate off- 
hook call announces, however, it cannot receive 
them. A station user is allowed or denied the ability 
to originate the Off-hook Call Announce feature in 
the DCOS Program. In order to receive the Off- 
hook Call Announce feature, a PCB (DVSU) is 
required to be installed in each affected digital  FIGURE 4-45-INSTALLATION OF 
4-34  
						

							telephone, and the NDKU must be set for option 2 
(see Paragraph 3.45 of this chapter). 
6.22 A DVSU PCB inside a lOOO-series digital 
telephone allows the digital telephone to receive 
the Off-hook Call Announce feature. 
NOTE: 
It is not recommended to equip digital tele- 
phones with both Off-hook Cal/Announce and 
the headset option at the same time. 
6.23 The installation of the DVSU PCB must be 
done in accordance with the following steps: 
1) Loosen the four captive screws securing the 
telephone’s mounting base (Figure 4-43), and 
remove the base. 
2) Loosen the four captive screws securing the 
metal plate to the standoffs inside the base 
where the DVSU PCB will be installed (Figure 
4-46). Remove the metal plate and discard it. 
3) Position the DVSU PCB on the standoffs 
Make sure that the DVSU wire 
TO DVSU plugs are inserted into the 
correct UPPER and LOWER 
CONNECTOR 
PCB connectors of the 
ON UPPER PCB telephone. Do not plug DVSU 
INSIDE into HHEU connector. 
TELEPHONE IMPORTANT!  IMPORTANT! 
.I-,-- 
-----? that the DVSU wire 
! inserted into the 
‘PPER and LOWER 
nnectors of the 
ON LOWER PC 
TELEPHONE 
FIGURE 4-46-DVSU INSTALLATION 
INSTALLATION INSTRUCTIONS 
SECTlON200-255-204 
FEBRUARY1992 
(Figure 4-46), and secure it with the four 
screws provided. ’ 
4) Connect the DVSU wire plugs to the connec- 
tors labelled “DVSU”on both telephone’s PCBs 
(Figures 4-46 and 4-47). 
IMPORTANT NOTE.’ 
Make sure that the DVSU wire plugs are 
connected to the proper connectors. 
5) Reinstall the telephone’s mounting base 
(Figure 4-43), and secure it with its four cap- 
tive screws. 
6.24 A single pair of wires are required to connect 
the digital telephone to the NDKU port. OCA con- 
nection details are shown in Figure 4-42, the Digital 
Telephone Connection diagram. 
6.30 Carbon Handset Transmitter Installation 
6.31 If a customer-supplied carbon-type handset 
is used with the 1 OOO-series digital telephone, the 
two jumper straps on the telephone’s upper PCB, 
labelled “PERCEPTION-SUB (SPF),” must be cut. 
To cut the straps: 
1) Loosen the four captive screws securing the 
telephone’s mounting base (Figure4-43), and 
remove the base. 
FIGURE 4-47 
TELEPHONEPCBCONNECTIONSANDSTRAPS 
4-35  
						

							INSTALLATION INSTRUCTIONS 
SECTION 200-255-204 
FEBRUARY1992 
2) Refer to Figure 4-47, and locate the CARBON 
straps, W301 and W302, and cut them. 
3) Reinstall the telephone base (Figure 4-43), 
and secure it with its four captive screws. 
6.40 Beep Strap Removal 
6.41 A beep is emitted whenever a dialpad button 
or flexible button is pressed. This beep can be 
eliminated if the beep strap is cut. To cut the strap: 
1) Loosen the four captive screws securing the 
telephone’s mounting base (Figure 4-43), and 
remove the base. 
2) Refer to Figure 4-47, and locate the BEEP 
strap, W304, labelled “PERCEPTION1 O-SUB 
(SPF)” on the telephone’s upper PCB, and cut 
it. 
3) Reinstall the telephone’s mounting base (Fig- 
ure 4-43), and secure it with its four captive 
screws. 
6.50 Microphone/Speaker Threshold Adjust- 
ment (Speakerphone only) 
6.51 If the speaker frequently cuts off during 
handsfree operation, because of high ambient noise 
levels, set the ROOM NOISE switch to the high 
position. To set the switch: 
1) Loosen the four captive screws securing the 
telephone’s mounting base (Figure4-43), and 
remove the base. 
2) Refer to Figure 4-47, and locate the ROOM 
NOISE switch, labelled “PERCEPTION1 O- 
SUB (SPF)” on the telephone’s upper PCB. 
Carefully push the switch to the HIGH (H) 
position. 
3) Reinstall the telephone’s mounting base (Fig- 
ure 4-43), and secure it with its four captive 
screws. 
6.60 HHEU Installation 
6.61 The HHEU option provides the interface and 
control for a customer-supplied headset. It is in- 
stalled in accordance with the following steps: 
1) Loosen the four captive screws securing the telephone’s mounting base (Figure 4-43) and 
remove the base. 
2) Using a screw driver or other suitable tool, 
remove the plastic tab located on the back of 
the mounting base (Figure 4-43). The HHEU 
modularconnectorfor the headset is accessed 
through this opening. 
3) Set the SW601 switch on the HHEU PCB to 
the HEADSET position (Figure 4-48). 
4) If the headset receiver is not to receive OCA 
caller voice announcements, cut both sides of 
the R607 resistoron the HHEU PCB (Figure4- 
48), then remove the resistor. 
5) Position the HHEU PCB on the standoffs 
inside the base (Figure 4-48), and secure with 
the two screws provided. 
6) Connect the HHEU PCB to the telephone’s 
upper PCB, labelled “PERCEPTION1 O-SUB 
(SPF).” See Figure 4-47. 
COMPONENT SIDE OF HHEU (V.3 or later) 
FIGURE 4-48 
HHEU INSTALLATION FOR DIGITAL 
TELEPHONE 
4-36  
						

							7) Refer to Figure 4-47, and locate the HHEU 
strap, W303, on the upper PCB. Cut the strap 
if the HHEU PCB is to be connected to a 
headset. 
8) Reinstall the telephone’s mounting base and 
secure it with its four captive screws. 
6.70 Attendant Console Connection 
6.71 See Paragraph 5.50 for the attendant console 
connection. 
6.80 DSS Console Connections 
6.81 See the DSS Program in Section 200-255- 
300, Programming, to input information concern- 
ing the digital DSS consoles. 
6.82 The DSS console must be positioned adja- 
cent to a digital telephone (preferably an LCD 
model). DSS consoles use 2-pair wiring and are 
connected to the MDF via standard twisted-pair 
telephone cables. An RJ25 modular connector 
should be attached to the instrument-end of the 
telephone cable to permit connection to the DSS 
console. 
6.83 The overall length of the DSS console cable 
run from the equipment cabinet must not exceed 
1000 feet (304 M), 24 AWG cable. 
IMPORTANT! 
When installing the DSS console cable, do 
not run parallel to and within 3’ of an AC 
power line. Such power lines should be 
crossed at right angles (90”) only. 
6.84 DSS console(s) connection details are shown 
in Figures 4-49 and 4-50, for both PERCEPTION, 
and ex. 
6.90 DIGITAL DATA INTERFACE UNIT (PDIU) 
6.91 The Perceptione8ie, with D.04 software pro- 
vides two new style digital Data Interface Units 
(DIUs) that enable digital telephone users to si- 
multaneously transmit and receive data on the 
same NDKU station port and wire pair while com- 
INSTALLATION INSTRUCTIONS 
SECTION 200-255-204 
FEBRUARY1992 
municating on a voice call. One unit, called the 
integrated DIU (PDIU-DI) replaces the digital 
telephone’s base; the other unit is a small self- 
contained box called the stand-alone DIU (PDIU- 
DS). Each DIU is powered by the NDKU PCB it is 
connected to; therefore, no external power is re- 
quired. 
6.92 Both PDlUs can be connected to standard 
Electronic Industries Association (EIA) RS-232 
asynchronous serial data devices. EIA devices 
are divided into two categories: 
l Data communication equipment (DCE). Com- 
mon DCE devices are modems and some print- 
ers. 
l Data terminal equipment (DTE). Common DTE 
devices are personal computers, ASCII termi- 
nals, and some printers. 
.The PDIU-DI operates like a DCE, and it connects 
directly to DTE devices using standard RS-232 
cables. Depending on how its internal jumper 
plugs are configured, the PDIU-DS can either 
operate like a DTE and connect to DCE devices, or 
operate like a DCE device and connect to a DTE 
device. In most applications, DTE and DCE devices 
exchange data between each other via the stan- 
dard RS-232 cable connection. 
6.93 PDlUs can function with DCE and DTE de- 
vices at data speeds of up to 19.2kbps; however, 
keyboard dialing using AT commands (from a PC 
or a terminal connected to a PDIU) is limited up to 
9.6kbps. PDIU data transmission speed is set by 
the first AT command that the PDIU receives once 
it is in the command mode. The transmission 
speed is transparent to the PDIU if data is being 
sent via manual dialing or if the PDIU is receiving 
calls. 
NOTES: 
1. See the DDIU 
Program in Section 200- 
255-300 for information on programming 
the Digital Data interface Units. The sys- 
tem must be told which type of PDIU 
(-DI 
or -DS) is installed at each location. 
2. Digital Data interface Unit (PDIU-DI and 
PDIU-DS) connection details are shown 
in Figure 4-42, the Digital Telephone 
Connection diagram. 
4-37  
						

							INSTALLATION INSTRUCTIONS 
SECTlON200-255-204 
FEBRUARY1992 
NDKU PCB CONNECTOR 
t MODULAR JACK STATION CORD 
- TLl - 26 - W-EL 
CKT - RLl - 1 - BL-W 
1 
- DTLl - 27 - W-O 
- DRLl - 2 - O-W 
- TL2 - 20 - W-G 
CONSOLE #l 
CKT - RLZ! - 3 - G-W 
2 
- DTL2 - 29 - W-BR 
- DRL2 - 4 - BR-W 
- TL3 - 30 - W-S 
CKT - AL3 - 5 - s-w 
3 
- DTL3 - 31 - R-BL 
CONSOLE #3 
- DRL3 - 6 - BL-R 
- TL4 - 32 - R-O 
CKT - RL4 - 7 - O-R 
4 
- DTL4 - 33 - R-G 
CONSOLE #4 
- DRL4 - 0 - G-R 
FIGURE 4-49-DIGITAL DSS CONSOLE CONNECTION FOR PERCEPTION, “c” SLOT 
NDKU PCB CONNECTOR 
MODULAR JACK STATION CORD 
- TLl - 26 - W-BL 
- RLI - 1 - BL-W 
- DTLl - 27 - W-O 
CKl - DRLl - 2 - O-W 
1 
NOT 
USED 
- TL3 - 30 - W-S 
- RL3 - 5 - S-W 
- DTL3 - 31 - R-BL 
CKT - DRLB - 10 --L-R 
3 
NOT 
USED 
- TL5 - 34 - R-BR 
- RL5 - 9 - BR-R 
- DTL.5 - 35 - R-S 
CKT 
- DRL5 - 10 - S-R 
5 
NOT 
USED 
CKT 
7 - n-7 - 38 - BK-G 
- RL7 - 13 - G-BK 
- DTL7 - 39 - BK-BR 
- DRL7 - 14 - BR-BK 
NOT 
USED 
CONSOLE #4 
I-Ibunt 
4-su 
DIGITAL DSS CONSOLE CONNECTION FOR PERCEPTION, “U” SLOTS AND PERCEPTION, ‘I” SLOTS 
4-38