The T-BERD 209osp is a portable test instrument that comprehensively analyzes T1 transmission systems. Designed for outside plant testing, the T-BERD 209osp may be used during circuit installation, acceptance testing, and fault isolation. Weather-resistant construction permits the T-BERD 209 osp to operate in harsh environments. A membrane-switch front panel and a seamless, molded plastic case protects the T-BERD 209osp against the entry of water and debris. All connections, where water or dirt might be introduced, are isolated from the mainframe electronics by a water-resistant barrier. AUTOTEST™ feature performs a sequence of automated tests on a T1 circuit. These tests include: BRIDGTAP automated pattern sequence, Repeater test, optional DC measurements tests, and optional TDR test. This feature requires the T-BERD T1 Repeater Adaptor accessory. Automated BRIDGTAP™ pattern sequence detects bridge taps on a T1 span by automatically generating 21 test patterns and monitoring the returned signal for errors. Automated MULTIPAT™ pattern sequence generates five standard test patterns in 15 minutes. This feature eliminates the need to perform separate tests with each pattern. D1D, D4, ESF, SLC-96, and unframed framing patterns offer compatibility with a variety of framing formats. Two front panel displays provide verification of instrument configuration and test results. Repeater test verifies each side of a repeater with PASS/FAIL results. This feature requires the T-BERD T1 Repeater Adaptor accessory. Logic error, bipolar violation, and frame error analysis are performed simultaneously. Complete signal analysis includes signal level, timing slips, received clock frequency, and simplex current measurements. In-band and out-of-band ESF loopback codes enable the instrument to loopback or emulate devices that accept either in-band or out-of-band datalink loop codes. Bit-Patterned Message (BPM) recognition enables the T-BERD 209osp to identify and display BPMs from the ESF datalink in accordance with ANSI T1.403. In addition, the T-BERD 209osp can generate BPMs. SUMMARY category displays either ALL RESULTS OK or any out-of-specification or non-zero results, eliminating the need to search through long lists of test results. AUTO mode automatically configures the T-BERD 209osp to synchronize to the received T1 signal. No setup is required when monitoring live circuits. Logic error and bipolar violation (BPV) insertion enables the T-BERD 209osp to simulate errors. Line build-out (LBO) selections add troubleshooting capability to uncover marginal problems such as cable crosstalk and bridge taps. Print capability generates instrument setup, test results, and TDR trace printouts. Rechargeable lead-acid battery provides eight to ten hours of continuous cord-free operation.