MT9234ZBA-NAM-CP Multi-Tech Systems, MT9234ZBA-NAM-CP Datasheet
MT9234ZBA-NAM-CP
Related parts for MT9234ZBA-NAM-CP
MT9234ZBA-NAM-CP Summary of contents
Page 1
MultiModem MT9234 Series AT Commands Reference Guide ® & SocketModem ® ...
Page 2
... AT Commands Reference Guide for the MultiModem and SocketModem MT9234 Series MT9234SMI MT9234ZBA MT9234ZBA-USB MT9234MU MT9234ZPX-UPCI MT9234ZPX-PCIE ISI9234PCIE PN S000434H, Version H Copyright This publication may not be reproduced, in whole or in part, without prior expressed written permission from Multi-Tech Systems, Inc. All rights reserved. Copyright © 2007-2010, by Multi-Tech Systems, Inc. ...
Page 3
... XON/XOFF Pass-Through .......................................................................................................... 20 -C Data Calling Tone ...................................................................................................................... 20 %A Adaptive Answer Result Code Enable .................................................................................... 20 %B View Numbers in Blacklist ....................................................................................................... 20 %C Data Compression Control ...................................................................................................... 21 %DC AT Command Control ........................................................................................................... 21 %DT Set AT Command Mode Timer ............................................................................................ 21 Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Contents Table of Contents 3 ...
Page 4
... Local Callback Inactivity Timer ............................................................................................. 36 #CBN Store Callback Password ..................................................................................................... 36 #CBP Callback Parity ..................................................................................................................... 37 #CBR Callback Security Reset ....................................................................................................... 37 #CBS Callback Enable/Disable ...................................................................................................... 37 S-Registers ............................................................................................................................................. 38 Result Codes .......................................................................................................................................... 41 Chapter 4 – Voice Commands ................................................................................................................. 43 Introduction ............................................................................................................................................ 43 Voice S-Register Summary ................................................................................................................... 44 Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Table of Contents 4 ...
Page 5
... Voice Mode Result Codes ..................................................................................................................... 57 Unsolicited Voice Mode Result Codes ................................................................................................ 58 Valid Complex Event Report Tags ...................................................................................................... 58 Voice Mode Shielded Codes ................................................................................................................. 59 DTE/DCE Interface Rates ...................................................................................................................... 61 Chapter 5 – Country/Regional Code Configuration ............................................................................... 62 Index ........................................................................................................................................................... 63 Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Table of Contents 5 ...
Page 6
... Fax Service Class 1 and Fax Service Class 1.0 Developer's Guide. Document number: S000262x • Fax Developer's Guide for Classes 2 and 2.0/2.1 Document number: S000239x Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 6 ...
Page 7
... Select Bell 103J when the modem is at 300 bps. Defaults: 0 and 15 Result Codes <value> = 0-3, 15, 16 ERROR if <value> ≠ 1. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes (R ) key to execute a command. ETURN ). ...
Page 8
... See &D<value> – Data Terminal Ready (DTR) Control. ERROR if the modem is in on-line command mode when receiving the A command. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 8 ...
Page 9
... ATH<value> Values on-hook (hang up off-hook (make the phone line busy). Default: 0 Result Codes <value> ERROR if <value> ≠ Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 9 ...
Page 10
... Speaker on until carrier is detected, except while dialing. Default: 1 Result Codes <value> ERROR if <value> ≠ Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Status V.92 28800 50666 28800 50666 ...
Page 11
... ERROR result code because result codes are turn off. Syntax: ATQ<value> Values: 0 Enable result codes. 1 Disable result codes. Default: 0 Result Codes <value> ERROR if <value> ≠ Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 11 ...
Page 12
... CONNECT result code reports DCE receive speed; enables protocol result codes. Default: 2 Result Codes <value> ERROR if <value> ≠ Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 12 ...
Page 13
... Default: None Result Codes <value> ERROR if <value> ≠ Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Enabled Modem displays basic result codes, connect messages with data rate, and an indication of ...
Page 14
... There are several noted exceptions to this command and caution should be used when determining the state of the command options once this command has been executed. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 14 ...
Page 15
... Selects 33% to 67% make-to-break ratio at 20 pulses per second. Default: 1 Note: The &P2 command is available only if the country/regional code is set to Japan. Result Codes <value> ERROR if <value> ≠ Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 15 ...
Page 16
... CONNECT if <value> ERROR if <value> ≠ &V View Active Configuration Description: Use this command to view the active configuration. Syntax: AT&V Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 16 ...
Page 17
... Syntax: AT\A<value> Values: 0 64-character maximum 1 128-character maximum 2 192-character maximum 3 256-character maximum Default: 3 Result Codes <value> ERROR if <value> ≠ Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 17 ...
Page 18
... Result Codes <value> ERROR if <value> ≠ Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Function Enter online command mode, no break sent to remote modem. ...
Page 19
... Result Codes <value> ERROR if <value> ≠ Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Specifies the length of time in minutes that the modem will wait before disconnecting when no data is sent or received. ...
Page 20
... Result Codes: <list of phone numbers and their status> if country supports blacklisting failed calls occur. ERROR if country selection does not support blacklisting. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 20 ...
Page 21
... Sets callback security to normal operation. 1 All callback security calls will be direct connect regardless of whether the password or phone number has the - character. Default: 0 Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 21 ...
Page 22
... Set the V.8 CI signal call function to the hexadecimal octet XY. 00 (Default Reporting: +A8E? Reports current or selected values. +A8E=? Reports supported parameter values. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 22 ...
Page 23
... Result Codes <v42bis> and <v44> ERROR if <v42bis> ≠ <v44> ≠ Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Reports current or selected values. Reports supported parameter values. ...
Page 24
... Reporting: +DS? +DS=? Result Codes: OK ERROR Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Disables the V.44 compression report. Enables the V.44 compression report. Reports current or selected values. Reports supported parameter values. V.42bis is in use in both directions. ...
Page 25
... Example: +DS44: (3, 0), (0), (0), (256-2048), (256-2048), (31-255), (31-255), (512-11008), (512-11008). +DS44? Reports current or selected options. Example: +DS44 1024, 1024, 255, 255, 5120, 4096. Result Codes: OK ERROR Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 25 ...
Page 26
... Result Codes: +ER: NONE +ER: LAPM +ER: ALT OK ERROR Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Data compression not in use. V.42 LAPM protocol is in use. V.42 alternative protocol is in use. if <value> <value> ≠ ...
Page 27
... Reports: +ETBM? +ETBM=? Result Codes: OK ERROR Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Mode Buffered mode Direct mode MNP or disconnect mode LAPM or disconnect mode MNP or buffered mode ...
Page 28
... Reports current or selected options. +GMM=? Reports supported options. Result Code: OK Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Selects data mode. Selects Class 1.0 FAX mode. Selects Class 1 FAX mode. Selects Class 2 FAX mode. ...
Page 29
... Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes No flow control. Software flow control. Hardware flow control. (Default) Reports current or selected options. Reports supported options. ...
Page 30
... The settings of this command overwrite the settings of S28 and S37. Likewise, changes to these registers overwrite the settings of the +MS command. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Reports current or selected options. ...
Page 31
... V32 V22bis V22 V23C, Bell212A 1200 bits/s V.21, Bell103 Reports: +MS? +MS? Result Code: OK ERROR Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes V.92 (default) V.90 V.34 V.32bis V.32 V.22bis V.22 Bell 212A* V.23, constant carrier, asymmetric FDM ...
Page 32
... Syntax: AT$LL<value> Values: 0 Implements V.34 handshake per standard specification. 1 Implements V.34 handshake per leased line specification. Default: 0 Result ERROR if not Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 32 ...
Page 33
... Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Sets serial port to 300 bps Sets serial port to 1200 bps Sets serial port to 2400 bps Sets serial port to 4800 bps ...
Page 34
... Syntax: AT#S=x Values: x stands for password (1–8 characters, case sensitive) Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Disables Distinctive Ring cadence reporting. Enables Distinctive Ring cadence reporting. Other call progress result codes (including RING) are reported as normal ...
Page 35
... Default: 0 Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Disables Caller ID Enables Caller ID with formatted data Enables Caller ID with unformatted data Displays the allowed values Displays the current value ...
Page 36
... Sets the callback security password for the y memory location. The password must have characters, and cannot include the + or - characters. Syntax: AT#CBN<y=x> Values 0– password Defaults: None Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 36 ...
Page 37
... Disables callback security. Default. 1 Enables local and remote callback security. 2 Enables remote callback security only. 3 Disables callback security until local hang-up or reset. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes 37 ...
Page 38
... S36 decimal 0–7 7 Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Description Sets the number of rings until the modem answers. ATS0=0 disables auto answer completely. Counts the rings that have occurred. ...
Page 39
... S38 decimal 0–23 1 S43 decimal 0–1 1 Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Sets the maximum V.34 “upstream” speed at which the modem attempts to connect maximum speed 1 = reserved 2 = 1200/75 bps ...
Page 40
... S89 seconds 0, 5–65 0 Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Enables (7) or disables (128) LAPM negotiation . The following table lists the S36 and S48 configuration settings for certain types of connections ...
Page 41
... CONNECT 28000 101 CONNECT 29333 102 CONNECT 30666 Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Description Command executed Modem connected to line Ring signal detected Carrier signal lost or not detected ...
Page 42
... MNP5 – MNP 4 error control and MNP 5 data compression MNP4 – MNP 4 error control only NoEC – No error control protocol. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 1 – AT Commands, S-Registers, and Result Codes Connected at 33333 bps ...
Page 43
... Service Level C provides the highest service level with the addition of facsimile calling tone and Busy detection during receives, Dial Tone detection, and double-tone detection. An example of event detection in a Service Level C modem is shown below: AT+VEM=? "C" 0A000100 0E601800 1A803840 OK Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 4 – Voice Commands 43 ...
Page 44
... Voice mode. +FCLASS=8 Places the modem in Voice mode. +FCLASS= New values are added for Voice mode. +FCLASS=? New values are added for Voice mode. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 4 – Voice Commands 44 ...
Page 45
... None Result Codes: OK ERROR if not in voice mode. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Enables automatic hang-ups as in non-Voice modes (such as hanging up the phone when the modem does not detect a data carrier within a given time interval). ...
Page 46
... AT+VTS=? (200-3300), (200-3300), (0-500) OK Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) A single character which the modem interprets as a DTMF digit (0– and A–D) or hookflash (!), with a duration given by the +VTD command. ...
Page 47
... Result Codes the modem accepts the command ERROR if the parameter is out of range. Reports: +VGT? Displays current or selected values. +VGT=? Displays list of valid values supported. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 4 – Voice Commands 47 ...
Page 48
... Result Codes <timer> = 0-255. ERROR if the parameter is out of range or if not in voice mode. Reports: +VIT? Displays current or selected values. +VIT=? Displays list of valid values supported. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 4 – Voice Commands 48 ...
Page 49
... Response: <label>,<devices>,transmit event>,<receive event>,<idle event> where <label> <devices> <xxxx event> Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 4 – Voice Commands Description Modem on-hook. Local phone connected to Telco. Default. Modem off-hook, and connected to Telco. Local phone provided with power to detect hook condition ...
Page 50
... OK if <interval> = 0-25. ERROR if the <interval> parameter entered is out of range or the modem is not in voice mode. Reports: +VRN? Displays current or selected values. +VLN=? Displays a list of the supported values. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 4 – Voice Commands 50 ...
Page 51
... Displays current or selected values. +VSD=? Displays a list of the supported values. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Use +VSM silence compression setting and algorithm for long-term silence detection if +VSM is in use OR Use default long-term setting silence detection level and algorithm if +VSM is not in use ...
Page 52
... Reports the following: Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) <cml> See above <cmid> An alphanumeric string describing the compression method (UNSIGNED PCM, IMA ADPCM, 2-Bit ADPCM, or 4-Bit ADPCM) < ...
Page 53
... DROF=40 Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) 0 The modem will not generate ring cadence reports. Other call progress event codes (including Ring) are reported as normal. 1 The modem will report ring cadence information as specified for the < ...
Page 54
... Note that the displayed hex values are not connected to the <mask> parameter in the +VEM and +VEM? commands. Result Codes the modem accepts this command ERROR if the bit field contains illegal characters. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 4 – Voice Commands 54 ...
Page 55
... OK if the modem accepts the command ERROR if either the <assert> or <deassert> parameter is greater than the buffer size the <de-assert> parameter is greater than or equal to the <assert> value. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 4 – Voice Commands 55 ...
Page 56
... AT commands at 2400 bps at all times while in Voice command mode and with +VPR=0. Result Codes the modem accepts the command. ERROR if the <rate> value is out of range. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 4 – Voice Commands 56 ...
Page 57
... Lost Data Detected Event 32 Facsimile Answer 33-63 Reserved for future standard above 63 Manufacturer specific _____ * Further study required for final specification. The TIA/EIA-602 CONNECT result code is disallowed in voice mode. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 4 – Voice Commands 57 ...
Page 58
... In the event of an unrecognized data tag, the SocketModem presents the data item information as printable hex ASCII numbers following the MESG tag. For example: RING DATE=0321 TIME=1405 NMBR=5045551234 NAME=DOE JOE MESG=060342424231 RING RING Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 4 – Voice Commands 58 ...
Page 59
... Event Number 9 (Presumed Hang Up " q (71) Event Number 10 (Presumed End of Message "QUIET" Timeout). J (4A) Event Number 11 (SIT Tone). $ (24) Event Number 12 (Bong Tone). Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 4 – Voice Commands " Timeout). SILENCE 59 ...
Page 60
... Event Number 48 (manufacturer specific). ' (27) Event Number 49 (manufacturer specific). ( (28) Event Number 50 (manufacturer specific). ) (29) Event Number 51 (manufacturer specific). all other 7-bit ASCII Reserved for future use. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 4 – Voice Commands 60 ...
Page 61
... Projected DTE/DCE Interface Rates for 7.2/8K Hz Sample Rates Bits per Sample 0 Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Projected DTE/DCE Projected DTE/DCE I/F Rate @ 7.2K Hz I/F Rate @ 8K Hz 4800 9600 9600 19200 19200 19200 38400 38400 38400 57600 57600 57600 ...
Page 62
... The Global Modem Country/Region Approvals page displays. On this page you can view approvals, configuration strings (includes the country/regional code) and responses available in list form by selecting country/region and/or product. Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Chapter 5 – Country/Regional Code Configuration AT Command (Hexadecimal) ...
Page 63
... Store Current Configuration ............................ 17 &Z – Store Dialing Location and Number ................. 17 &Zy= – Store Dialing Location and Number for Callback Security ................................................. 17 Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Index + +++AT – Escape Sequence ....................................... 7 +A8E – V.8 and V.8bis Operation Controls .............. 22 +A8T – ...
Page 64
... Dialing tones – S11 .................................................. 38 Distinctive Ring (Ring Cadence Reporting) – +VDR 53 Distinctive Ring Report – +VDR ............................... 34 Downstream Data Rate – S38................................. 39 Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) DTE/DCE Interface Rate (Turn Off Autobaud) – +VPR ............................................................................. 56 DTE/DCE Interface Rates ........................................ 61 DTE-DCE Local Flow Control – ...
Page 65
... Set AT Command Mode Timer – %DT ..................... 21 Set Callback Security – Direct Connect Enable – %H ............................................................................. 21 Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H) Set Register Value – Sr ............................................ 12 Set Sleep Mode – S24 ............................................. 38 Set the Volume for Transmitted Voice Samples – ...
Page 66
... Voice Mode Shielded Codes .................................... – Result Code Options ......................................... 12 Wait time for dial tone – S6 ...................................... 38 Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H – Select Result Code & Call Monitor Progress ..... 13 X – XON/XOFF Pass-Through ................................. 20 XON/XOFF Pacing Control – ...